Dear Tom,
Weather-knowledgeable friends say large hail always comes before a tornado, but I wonder about that. Is it true?
— Peter Micham, southwest suburbs
Dear Peter,
It is not true. Only the wind fields within and in the area several miles around a severe thunderstorm provide reliable clues as to the storm’s tornado-producing capabilities. Unfortunately, those telltale signs are rarely apparent to an observer. Only Doppler radars can detect them.
Severe-storms forecaster Roger Edwards of the National Weather Service’s Storm Prediction Center in Norman, Okla., says: “Does hail always come before a tornado? Rain? Lightning? Utter silence? High winds? Not necessarily for any of those. Hail can indicate the presence of an unusually dangerous thunderstorm, but it is not a reliable predictor of tornado threat.”
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Write to: ASK TOM WHY, 2501 Bradley Pl., Chicago, IL 60618 or: asktomwhy@wgntv.com
Weather Report is prepared by the WGN-TV Weather Center, where Tom Skilling is chief meteorologist. His forecasts can be seen Monday through Friday on WGN News at noon, 5:55 p.m. and 9 p.m.
WGN-TV meteorologists Steve Kahn, Richard Koeneman and Paul Dailey plus weather producer Bill Snyder contribute to this page.
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