the type of thunderstorm that has the most damaging winds and precipitation is a
Thunderstorm A thunderstorm is classed as severe if winds reach at least 93 kilometres per hour (58 mph), hail is 25 millimetres (1 in) in diameter or larger, or if funnel clouds or tornadoes are reported.[29][30][31] Although a funnel cloud or tornado indicates a severe thunderstorm, a tornado warning is issued in place of a severe thunderstorm warning. A severe thunderstorm warning is issued if a thunderstorm becomes severe, or will soon turn severe. In Canada, a rainfall rate greater than 50 millimetres (2 in) in one hour, or 75 millimetres (3 in) in three hours, is also used to indicate severe thunderstorms.[32] Severe thunderstorms can occur from any type of storm cell. However, multicell, supercell, and squall lines represent the most common forms of thunderstorms that produce severe weather.[12]
Weather-related fatalities in the United States Weather-related fatalities in the United States may be caused by extreme temperatures, such as abnormal heat or cold, flooding, lightning, tornado, hurricane, wind, rip currents, and others. The National Weather Service compiles statistics on weather-related fatalities and publishes reports every year.[1] In 2016, flooding was the number-one cause of weather-related fatalities, but over a 30-year period, on average, extreme heat is the deadliest form of weather.[2]