Dear Tom,
News reports incorrectly stated the winds in last week’s deadly F5 Greensburg, Kansas, tornado as “reaching 200 m.p.h.” The F5 speed range is 261-318 m.p.h.
Lawrence Janus
Dear Lawrence,
The reports that you heard were referencing the new “Enhanced Fujita” (EF) tornado scale adopted this year by the National Weather Service, and they are correct.
Dr. Fujita?s original F-scale of tornadic wind speeds, published in 1971, established six speed categories, F0 through F5, with the highest range pegged at 261-318 m.p.h. Since then, wind-speed researchers have come to realize those speeds were too high and so they carefully devised the “enhanced” scale, whose top category, EF5, is now defined as “over 200 m.p.h.”
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Tom Skilling is chief meteorologist at WGN-TV. His forecasts can be seen Monday through Friday on WGN-TV News at noon and 9 p.m.
WGN-TV meteorologists Steve Kahn, Richard Koeneman and Paul Dailey plus weather producer Bill Snyder contribute to this page.
