Sound waves travel much more slowly, so a thunderclap may come many seconds after the lightning is spotted.Thunderstorms kill approximately 200 people in the United States and injure about 550 Americans per year, mostly from lightning strikes. NSSL Research: Thunderstorms. 4. A tornado is a violently rotating column of air that extends from a thunderstorm and comes into contact with the ground, according to the National Oceanic and Atmospheric Administration (NOAA). Loud rumbles and spectacular lightning bolts get far more notice in Spokane than in Chicago or Miami. The thunderstorm data use 1961 to 1990 averages. The map below shows the number of days with thunderstorms in the contiguous U.S. states. With an annual average of 89 thunderstorms, Fort Myers, Florida, is the thunderstorm capital of the U.S. And that’s not some climatic anomaly, either. To highlight how few thunderstorms occur along the West Coast every year, we can look at climate data taken from some of the region's largest cities. New Orleans tops the list of US cities that tolerate the greatest number of major rainstorms a year. They are most common in the U.S., where they can produce tornadoes, floods, lightning and damaging winds. Tornado intensity is measured by the enhanced Fujita (EF) scale. Areas over west central Florida experience more thunderstorms per year on average than any other location in the U.S. with > 100 per year (See graph above). There can be as many as 40,000 thunderstorms each day around the world. In an average year about 1,000 tornadoes are reported nationwide, according to NOAA. In the United States alone, an estimated 100,000 thunderstorms occur each year. Key West averages 64 days per year with thunderstorms with August averaging 14 and July 13 as the 2 most active months for thunderstorms … Our mission is to help make forecasts and warnings of thunderstorms more accurate to minimize their impact on our society. A: Any of the states along the Gulf Coast would make the list, McRoberts says. Most Heavy Rainstorms. The National Weather Service considers a thunderstorm severe if it produces hail at least three-quarters of an inch in diameter, winds of 58 mph or stronger, or a tornado. Altogether, 11 American cities put up with over 13 days a year of heavy rain. It is estimated that approximately 100,000 to 125,000 thunderstorms occur in the United States each year. Of that total anywhere from 10 to 20 percent may be severe. But the reason why tropical systems frequent this state is the same reason thunderstorms and lightning do too: the warm and humid waters of the Gulf of Mexico are at its doorstep. Protecting Hoosiers since 2015, the IDHS Safe Room Program has helped residents and communities statewide install hardened structures specifically designed to provide "near-absolute protection" in extreme weather events, like tornadoes. Thunderstorms can produce damaging straight-line winds, hail, heavy rain, deadly lightning and tornadoes. Take the Thunderstorm Quiz The city averages nearly 20 days annually when an inch or more of rain pelts down. The records keep count of the number of days that featured thunderstorms each year, along with the average number of thunderstorm days seen over the thirty year period between 1981 and 2010. 813,234 average CG flashes per year; 17.6 Flashes per sq mi; Fatalities 2006-2015: 12; When you think of Louisiana, hurricanes, not lightning, may first come to mind. Where the Windy City gets an average of 39 thunderstorms each year, our Lilac City gets 11. On multiple days this May, severe thunderstorms struck from Tennessee to Texas and tornadoes swept parts of Oklahoma and Colorado. “Mississippi, Alabama and Louisiana all have between 50 to 100 thunderstorm days per year… In an average year, 800 tornadoes are reported nationwide, resulting in 80 deaths and more than 1,500 injuries. To determine which places have more thunderstorms than others, scientists record the number of days thunder is heard, and also the number of days lightning strikes are seen, at weather stations across the country.