John Wheeler, WDAY, Published April 30 2014
Weather Talk: On average, 1,200 twisters touch down in US annuallyIt is estimated that about 1200 tornadoes touch down somewhere in the United States each year, on average. There are about 60 deaths per year, on average, attributable to these 1200 tornadoes, meaning there is about one death for every 20 tornadoes. The most common EF0 (wind speed 65-85 mph) and EF1 (wind speed 86-110 mph) tornadoes rarely result in fatalities. They generally are capable of more minor damage. About half the tornado deaths, on average, are caused by the rarest EF4 (wind speeds 166-200 mph) and EF5 (wind speeds greater than 200 mph) tornadoes, which make up about one per cent of all tornadoes. These are the tornadoes that are capable of destroying structures, and even small towns, completely. These most powerful tornadoes are the ones usually responsible for large numbers of fatalities at once. The 1957 north Fargo tornado was in this category. Most of the other tornados are caused by EF2 (wind speed 111-135 mph) and EF3 (136-165 mph) tornadoes and happen one or two at a time. The EF rating is determined by surveying the type of damage caused by a tornado. A tornado is rated by its highest rating, even though it is not at that strength over its entire course.
– John Wheeler, WDAY
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