Haze

 ( Visibility ) 

A Haze is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. A tornado is a violently rotating column of air extending from a thunderstorm to the ground, capable of immense destruction. While most are weak, brief, and narrow, the most powerful tornadoes can have wind speeds over 300 mph, stretch for more than a mile, and stay on the ground for hours. The United States experiences the most tornadoes of any country, averaging about 1,200 annually, primarily in the central and southeastern regions known as "Tornado Alley" and "Dixie Alley". Tornado formation and life cycle Tornadoes form from intense thunderstorms, most often supercells, where the atmosphere is highly unstable and features significant wind shear—a change in wind speed and direction with altitude. Formation Wind shear creates rotation: Wind shear creates a horizontal, tube-like rotation of air in the lower atmosphere. Updraft tilts the rotation: A thunderstorm's powerful updraft of warm, moist air can tilt this horizontal tube of spinning air into a vertical position. Funnel cloud forms: As the updraft continues to intensify, it creates an area of low pressure at the surface, pulling the rotating column of air downward. A visible condensation funnel may then form. Tornado touches down: When the rotating column of air makes contact with the ground, it officially becomes a tornado. The initial contact may only be marked by a swirl of dust and debris, even if a visible funnel has not fully descended. Life cycle of a supercell tornado Organizing stage: The tornado begins to take shape as the supercell's rotating mesocyclone lowers toward the ground. Mature stage: The tornado reaches peak intensity and destructive power, which can last for several minutes or over an hour. During this time, a cold, descending downdraft of air known as the Rear Flank Downdraft (RFD) begins to wrap around the vortex. Dissipating stage: The RFD eventually chokes off the tornado's supply of warm, moist air. The vortex narrows and twists into a rope-like shape, becoming weaker but still capable of causing damage. Types and appearance Tornadoes vary in shape, size, and type, with their appearance influenced by lighting and the environment. Types of tornadoes Supercell tornadoes: Most powerful and destructive tornadoes that form from supercell thunderstorms. Landspouts: A type of tornado not associated with a rotating updraft, similar to dust devils but stronger. They form from the ground up. Waterspouts: Tornadoes that form over water. "Fair weather" waterspouts are weaker and more common, while "tornadic" waterspouts are stronger and originate from severe thunderstorms. Multiple-vortex tornadoes: Consist of two or more smaller, sub-vortices orbiting a common center. They are often seen in intense tornadoes. Appearance Color: The color of a tornado can range from nearly invisible in dry conditions to white, gray, or blue over water. It can also appear red or dark brown from debris and soil. Shape: Shapes include narrow, rope-like swirls; wide, cylindrical "stovepipe" funnels; or massive, block-like "wedge" funnels. Hidden tornadoes: Some tornadoes are hidden by rain or low-hanging clouds, making them especially dangerous. Classification and measurement Tornado intensity is measured using the Enhanced Fujita (EF) Scale, which was implemented in the U.S. in 2007. The Enhanced Fujita Scale The EF Scale ranks tornadoes from EF0 to EF5 based on estimated wind speeds and observed damage. EF0 (65–85 mph): Minor damage, such as broken branches and shingles removed. EF1 (86–110 mph): Moderate damage, like stripped roofs and mobile homes overturned. EF2 (111–135 mph): Considerable damage, including entire roofs torn off and mobile homes demolished. EF3 (136–165 mph): Severe damage, with homes destroyed and trains overturned. EF4 (166–200 mph): Devastating damage, including well-built homes leveled. EF5 (>200 mph): Incredible damage, with strong-framed homes swept clean from their foundations. Effects and impacts Tornadoes cause devastating effects, both immediate and long-term. Threats and damage High winds: The primary cause of damage, capable of ripping apart structures, uprooting trees, and throwing vehicles. Flying debris: Objects caught in the wind become deadly missiles, posing the greatest threat to living creatures. Pressure changes: Sudden atmospheric pressure shifts can cause buildings to explode outward if windows and doors are breached. Accompanying hazards: Heavy rain and large hail are common, and can cause flooding, power outages, and further damage. Financial cost: Tornadoes frequently contribute to billion-dollar weather events. Vulnerable structures Mobile homes: These are particularly vulnerable due to their lightweight construction and are easily damaged or destroyed. Long-span buildings: Large, open buildings like gyms and malls are dangerous because their roofs are often supported only by the outer walls and can collapse easily. Tornado safety and preparedness Taking precautions before, during, and after a tornado can minimize risk and increase chances of survival. Before a tornado Know the risk: Understand your area's tornado risk and the signs of an approaching tornado. Create a plan: Identify a safe shelter, such as a basement, storm cellar, or a small, interior, windowless room on the lowest floor of a sturdy building. Prepare a kit: Assemble an emergency kit with water, food, medications, flashlights, and a battery-powered radio. Stay informed: Pay attention to weather reports and sign up for community warning systems and NOAA Weather Radio alerts. During a tornado Seek shelter immediately: Do not wait until you can see or hear the tornado. Avoid windows and outside walls: Put as many walls as possible between yourself and the outside. In a mobile home: Evacuate immediately and seek shelter in a sturdy building. In a vehicle: Abandon the vehicle and seek low-lying shelter, such as a ditch or ravine. Never seek shelter under an overpass. Protect yourself: Cover your head and neck with your arms, a blanket, or a helmet to protect from flying debris. After a tornado Use caution: Be aware of potential hazards like downed power lines and leaking gas lines. Wear protective gear during clean-up. Stay informed: Continue monitoring updates from local authorities. Avoid damaged buildings: Do not enter damaged structures until authorities confirm they are safe. ally an atmospheric phenomenon in which dust, smoke, and other dry particulates suspended in air obscure visibility and the clarity of the sky. The World Meteorological Organization manual of codes includes a classification of particulates causing horizontal obscuration into categories of fog, ice fog, sea smoke, mist, haze, smoke, vog, Dust storm, Sandstorm, and snow. Sources for particles that cause haze include farming (stubble burning, ploughing in dry weather), traffic, industry, windy weather, Volcanism and . Seen from afar (e.g. an approaching airplane) and depending on the direction of view with respect to the Sun, haze may appear brownish or bluish, while mist tends to be bluish grey instead. Whereas haze often is considered a phenomenon occurring in dry air, mist formation is a phenomenon in saturated, humid air. However, haze particles may act as condensation nuclei that leads to the subsequent vapor condensation and formation of mist droplets; such forms of haze are known as "wet haze".

In meteorological literature, the word haze is generally used to denote visibility-reducing of the wet type suspended in the atmosphere. Such aerosols commonly arise from complex chemical reactions that occur as sulfur dioxide gases emitted during combustion are converted into small droplets of sulfuric acid when exposed. The reactions are enhanced in the presence of sunlight, high relative humidity, and an absence of air flow (wind). A small component of wet-haze aerosols appear to be derived from compounds released by trees when burning, such as terpenes. For all these reasons, wet haze tends to be primarily a warm-season phenomenon. Large areas of haze covering many thousands of kilometers may be produced under extensive favorable conditions each summer.

---

Air pollution Haze often occurs when suspended dust and smoke particles accumulate in relatively dry air. When weather conditions block the dispersal of smoke and other pollutants they concentrate and form a usually low-hanging shroud that impairs visibility and may become a respiratory health threat if excessively inhaled. Industrial pollution can result in dense haze, which is known as smog.

Since 1991, haze has been a particularly acute problem in Southeast Asia. The main source of the haze has been smoke from fires occurring in Sumatra and Borneo which dispersed over a wide area. In response to the 1997 Southeast Asian haze, the ASEAN countries agreed on a Regional Haze Action Plan (1997) as an attempt to reduce haze. In 2002, all ASEAN countries signed the Agreement on Transboundary Haze Pollution, but the pollution is still a problem there today. Under the agreement, the ASEAN secretariat hosts a co-ordination and support unit. ASEAN action hazeonline During the 2013 Southeast Asian haze, Singapore experienced a record high pollution level, with the 3-hour Pollutant Standards Index reaching a record high of 401.

In the United States, the Interagency Monitoring of Protected Visual Environments (IMPROVE) program was developed as a collaborative effort between the US EPA and the National Park Service in order to establish the chemical composition of haze in National Parks and establish air pollution control measures in order to restore the visibility of the air to pre-industrial levels. Additionally, the Clean Air Act requires that any current visibility problems be addressed and remedied, and future visibility problems be prevented, in 156 Class I Federal areas located throughout the United States. A full list of these areas is available on EPA's website.

In addition to the severe health issues caused by haze from air pollution, dust storm particles, and Wildfire smoke, reduction in irradiance is the most dominant impact of these sources of haze and a growing issue for Photovoltaics production as the solar industry grows. Smog also lowers Crop yield and it has been proposed that pollution controls could increase agricultural production in China. These effects are negative for both sides of agrivoltaics (the combination of photovoltaic electricity production and food from agriculture).

---

International disputes

---

Transboundary haze Haze is no longer just a confined domestic problem. It has become one of the causes of international disputes among neighboring countries. Haze can migrate to adjacent countries in the path of wind and thereby pollutes other countries as well, even if haze does not first manifest there. One of the most recent problems occur in Southeast Asia which largely affects the nations of Indonesia, Malaysia and Singapore. In 2013, due to forest fires in Indonesia, Kuala Lumpur and surrounding areas became shrouded in a pall of noxious fumes dispersed from Indonesia, that brings a smell of ash and coal for more than a week, in the country's worst environmental crisis since 1997.

The main sources of the haze are Indonesia's Sumatra Island, Indonesian areas of Borneo, and Riau, where farmers, plantation owners and miners have set hundreds of fires in the forests to clear land during dry weather. Winds blew most of the particulates and fumes across the narrow Strait of Malacca to Malaysia, although parts of Indonesia in the path are also affected. The 2015 Southeast Asian haze was another major crisis of air quality, although there were occasions such as the 2006 and 2019 haze which were less impactful than the three major Southeast Asian haze of 1997, 2013 and 2015.

---

Obscuration Haze causes issues in the area of terrestrial photography and imaging, where the penetration of large amounts of dense atmosphere may be necessary to image distant subjects. This results in the visual effect of a loss of contrast in the subject, due to the effect of light scattering and reflection through the haze particulate. For these reasons, sunrise and sunset colors and possibly the sun itself appear subdued on hazy days, and stars may be obscured by haze at night. In some cases, attenuation by haze is so great that, toward sunset, the sun disappears altogether before even reaching the horizon. Figure 1. "The setting sun dimmed by dense haze over State College, Pennsylvania on 16 September 1992".

Haze can be defined as an aerial form of the Tyndall effect therefore unlike other atmospheric effects such as cloud, mist and fog, haze is spectrally selective in accordance to the electromagnetic spectrum: shorter (blue) wavelengths are scattered more, and longer (red/infrared) wavelengths are scattered less. For this reason, many super-telephoto lenses often incorporate yellow light filters or coatings to enhance image contrast. Infrared (IR) imaging may also be used to penetrate haze over long distances, with a combination of IR-pass optical filters and IR-sensitive detectors at the intended destination.

---

See also

• Arctic haze
• ASEAN Agreement on Transboundary Haze Pollution
• Asian brown cloud
• Asian Dust
• Coefficient of haze
• Convention on Long-Range Transboundary Air Pollution
• Fog
• Mist
• Saharan Air Layer
• Southeast Asian haze
• Smog
• Trail Smelter dispute

---

Notes

---

External links

• National Pollutant Inventory - Particulate matter fact sheet
• Those hazy days of summer
• Haze over the central and eastern United States
• Chemical Composition of Haze in US National Parks: Views Visibility Database

Post Comment