Dear Tom,
In answer to a previous question, you said 1.4 million tons of water evaporated from California’s Lake Tahoe every day. So, what is the daily evaporation from our own Lake Michigan?
Jeanne K. Juricic, Crest Hill, Ill.
Dear Jeanne,
We speculated that the question about Lake Tahoe would prompt a similar query about evaporation from Lake Michigan. The answer is 93 times as much!
Most atmospheric processes operate on a scale that boggles the mind, and the evaporation of water from Lake Michigan into the atmosphere is no exception. The U.S. Geological Survey says 29.5 inches of water is lost from the lake’s surface annually via evaporation.
We did the math, and Lake Michigan’s surface (22,300 square miles) loses a staggering 130.6 million tons of water per day–93 times the amount lost from Lake Tahoe.
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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.)
WGN-TV meteorologists Steve Kahn, Richard Koeneman and Paul Dailey plus weather producer Bill Snyder contribute to this page.
