The Fujita (F) Scale was originally developed by Dr. Tetsuya Theodore Fujita to estimate tornado wind speeds based on damage left behind by a tornado. An Enhanced Fujita (EF) Scale, developed by a forum of nationally renowned meteorologists and wind engineers, makes improvements to the original F scale. This EF Scale has been approved by the National Weather Service (NWS) and will replace the original F scale, which has been used to assign tornado ratings since 1971.
The National Weather Services implemented an Enhanced Fujita (EF) scale in 2007 to rate tornadoes in a more consistent and accurate manner. The original F scale has limitations, such as a lack of damage indicators, no account for construction quality and variability, and no definitive correlation between damage and wind speed. These limitations may have led to some tornadoes being rated in an inconsistent manner and, in some cases, an overestimate of tornado wind speeds.
Enhanced Fujita Tornado Scale
3 Second Gust (mph)
Tornado Quick Facts
About 100,000 storms affect the U.S. each year, but only 1% produce a tornado.
One third (33%) of all tornado fatalities occur in mobile homes.
Tornadoes are most likely between 3 and 9 p.m. but have been known to occur at all hours of the day or night.
Learn additional facts and information by reviewing the U.S. Department of Commerce National Oceanic and Atmospheric Administration, National Weather Service, Quick Facts
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