HUMBERTO BECOMES A CATEGORY 5 MAJOR HURRICANE, IMELDA ON ITS WAY AS IT THREATENS THE EAST COAST OF THE U.S., GABRIELLE BECOMES POST-TROPICAL
Hurricanes form because of warm ocean water, which heats the air above it, causing moist air to rise. As the air rises and cools, it condenses into clouds and thunderstorms, releasing heat that fuels the storm. The Earth's rotation (Coriolis effect) makes the storm rotate, and low wind shear allows it to grow and strengthen. All of these factors combined lead to the formation of a hurricane.