Landfall is the event of a storm moving over land after being over water. More broadly, and in relation to human travel, it refers to 'the first land that is reached or seen at the end of a journey across the sea or through the air, or the fact of arriving there.'[ Definition of 'Landfall' in Cambridge Dictionary.]
Tropical cyclone
A
tropical cyclone is classified as making landfall when the center of the storm moves across the coast; in a relatively strong tropical cyclone, this is when the center of its eye moves over land.
[National Hurricane Center (2009). Glossary of NHC Terms: Landfall. Retrieved on 2009-02-05.] This is where most of the damage occurs within a mature tropical cyclone, such as a typhoon or hurricane, as most of the damaging aspects of these systems are concentrated near the
eyewall. Such effects include the peaking of the
storm surge, the core of strong winds coming ashore, and heavy flooding
Rain. These coupled with high surf can cause major
coastal erosion. When a tropical cyclone makes landfall, the eye usually closes in upon itself due to negative environmental factors over land, such as
friction with the terrain, which causes surf to decrease, and drier continental air. Maximum sustained winds will naturally decrease as the cyclone moves inland due to frictional differences between water and land with the free
atmosphere.
[Sim Aberson and Chris Landsea (2008). Subject : C2) Doesn't the friction over land kill tropical cyclones? Retrieved on 2009-02-05.]
Landfall is distinct from a direct hit. A direct hit is where the core of high winds (or eyewall) comes onshore but the center of the storm may stay offshore. The effects of this may be quite similar to landfall, as this term is used when the radius of maximum wind within a tropical cyclone moves ashore.[National Hurricane Center (2009). Glossary of NHC Terms: Direct Hit. Retrieved on 2009-02-05.] These effects are high surf, heavy rains that may cause flooding, minor storm surge, coastal erosion, high Wind, and possibly severe thunderstorms with Tornado around the periphery.
Storms, e.g., tropical cyclones, can be quite large. Potentially, dangerous winds, rain, and flooding may impact an area near the center of the storm, though technically landfall may not have occurred. Accordingly, it may be helpful to gauge the anticipated impact of such storms, to be aware of their general location and landmasses adjacent to the major thrust of the storm.
Tornado or waterspout
When a tornadic
waterspout makes landfall, it is reclassified as a tornado,
[Glossary of Meteorology (2009). Waterspout. Retrieved on 2009-02-05.] which can subsequently cause damage to areas inland. When a fair weather waterspout makes landfall, it usually dissipates quickly due to
friction and a reduction in the amount of warm air supplied to the
Funnel cloud.
[Bruce B. Smith (2009). Waterspouts. Retrieved on 2009-02-05.]
See also
