Asked in Hurricanes Typhoons and Cyclones
Why do cyclones lose intensity as they move inland?
August 29, 2010 10:51PM
Tropical cyclones (also known as hurricanes and typhoons) gain their energy from evaporation of warm ocean water. When this moisture rises and condenses, it release latent heat, which fuels the storm. As the cyclone moves over the land it no longer has this latent heat source, since there is very little water available for evaporation on land. Therefore, its energy source is effectively removed.
Additionally, the friction over land increases considerably from that over water, and this acts to weaken the storm's structure. This is especially true over rugged terrains, and mountains in particular. This is why a hurricane may hold together better over flat land, such as when it comes onshore around the Gulf of Mexico. But the same hurricane may be severely weakened just passing over a mountainous island such as Hispaniola or even Jamaica.