Dear Tom Skilling,
Say there are two clouds. Can one be moving faster than the other or just the same speed? Also, what is the record high speed for moving clouds? Lauren Melnick, Carol Stream, Ill.
Dear Lauren,
Since winds frequently vary in speed and direction with height, cloud layers at different altitudes can move faster or slower than one another. Horizontal cloud speed variations exist too (i.e. clouds in Illinois might well be moving faster than clouds in Wisconsin or Michigan).
Speed records are not kept for clouds, but the University of Wiscon-sins Dr. John Young says the fastest moving cloud fragments are those we see in a tornado. They can move at over 300 mph. Cirrus clouds in a jet stream may move up to 150 mph. Faster movements may appear to take place, but Young says what were really seeing is multiple cloud motions, which when viewed together give the appearance of extraordinary speed.
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Tom Skilling is chief meteorologist at WGN-TV. His weather forecasts can be seen Monday through Friday on WGN News at noon and 9 p.m.
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