Dear Tom,
Last week when Bonnie and Charley were threatening Florida I heard reference made to the Fujiwara effect. What is it?
Ben Beasley, Naperville
Dear Ben,
The Fujiwara effect, first documented by Japanese meteorologist Sakuhei Fujiwara more than 80 years ago, is a term used to describe the tendency of two tropical cyclones in close proximity to rotate about each other as a result of complex interactions between their circulations. This phenomenon occurs with some frequency in the western Pacific, but is rather rare in the Atlantic basin. The rotation between the two storms is always in a cyclonic direction–counterclockwise in the Northern Hemisphere and clockwise south of the equator. Some meteorologists were considering this interaction a possibility last week as the two tropical systems threatened Florida, but it did not occur.
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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.
Write to: ASK TOM WHY, 2501 Bradley Pl., Chicago, IL 60618 or asktomwhy@wgntv.com (Mail volume precludes personal response.)
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