Every thunderstorm produces lightning, which kills more people each year than tornadoes. Heavy rain from thunderstorms can lead to flash flooding. Strong winds, hail, and tornadoes are also dangers associated with some thunderstorms. Of the estimated 100,000 thunderstorms that occur each year in the United States, only about 10 percent are classified as severe. Most flash flood deaths occur at night and when people become trapped in automobiles.
Lightning Occurs with ALL thunderstorms.
Averages 93 deaths and 300 injuries each year. Causes several hundred million dollars in damage to property and forests annually. Straight-line Winds Responsible for most thunderstorm wind damage. One type of straight-line wind, the downburst, can cause damage equivalent to a strong tornado and can be extremely dangerous to aviation. During the summer in the western states, thunderstorms often produce little rain but very strong wind gusts and dust storms.