Hurricanes are intense low pressure areas that form over warm ocean waters in the summer and early fall. The main source of energy is water vapor which is evaporated from the ocean surface.
Water vapor is the ‘fuel’ for the hurricanes because it releases the latent heat of condensation when it condenses to form clouds and rain, warming the surrounding air. This heat energy is then absorbed by the water vapor when it is evaporated from the warm ocean surface, cooling the ocean in the process. Usually, the heat released in this way in tropical thunderstorms is carried away by wind shear, which blows the top off the thunderstorms. But when there is little wind shear, this heat can build up, causing low pressure to form. The low pressure causes wind to begin to spiral inward toward the center of the low.
Most hurricanes that hit the United States begin either in the Caribbean or the Atlantic. Many of the worst start as small tropical storms coming off the coast of Africa. Like all tropical cyclones, a hurricane needs the warm water of the tropics, which feeds a storm with energy, in order to form; the atmosphere must be laden with moisture. Researchers have looked at four factors that are known to affect hurricane intensity; wind shear that can throttle storm formation,rising sea-surface temperatures, and large-scale air circulation patterns.Sea-surface temperatures in the tropical North Atlantic have been the warmest on record for over the last decade. Warming temperatures heat up the surface of the oceans, increasing evaporation and putting more water vapor into the atmosphere. This in turn provides added ‘fuel’ for storms as they travel over open oceans.