Growth & Maturity
Composite imagery of Hurricane Rita from a tropical depression (1), tropical storm (2), hurricane (3), and major hurricane (4 and 5)
As the bands of thunderstorms contribute additional heat and moisture to the storm, it can strengthen to tropical storm status (number 2 in the figure) . The storm becomes a hurricane when winds reach a minimum of 74 mph (64 kt) (numbers 3, 4, and 5 in the figure). At this time, the cloud-free hurricane eye (number 4 in the figure) typically forms because rapidly sinking air at the center dries and warms the area.
During their life span, tropical storms and hurricanes can last for more than two weeks over the ocean. They can also change direction, sometimes hitting the same state more than once. For example, in 2008 Tropical Storm Fay made eight landfalls-including four in Florida. The storm produced torrential rainfall and a total of 82 tornadoes across five states.
