Florida has more thunderstorms than any other area of the United States. Thunderstorms affect relatively small areas when compared to hurricanes, however they occur much more frequently. The typical thunderstorm is 15 miles in diameter and lasts an average of 30 minutes. Nearly 1,800 thunderstorms are occurring at any moment around the world.
Despite their small size, all thunderstorms are dangerous. Every thunderstorm produces lightning, which kills more people each year than tornadoes. Heavy rain from thunderstorms can lead to flash flooding. Strong winds (straight-line winds or downbursts), hail and tornadoes are also dangers associated with some thunderstorms.
Straight-line winds, which are produced by the downward momentum in the downdraft region of a thunderstorm, are responsible for most thunderstorm wind damage. Some of these winds can exceed 100 mph. A downburst is a small area of rapidly descending air beneath a thunderstorm. When these occur, many times clouds are pulled toward the ground with the wind and give a tornado-like appearance.
Of the estimated 100,000 thunderstorms that occur each year in the U.S., only about 10 percent are classified as severe. The National Weather Service considers a thunderstorm severe if it produces hail at least 3/4-inch diameter, wind 58 + mph or tornadoes.