Dear Tom:
Some temperature forecasts include the phrase “cooler near the lake”. Just how far from the lake does this area extend to?
James Scalzitti, Chicago
Dear James,
There is no standard for how far inland “near the lake” encompasses; it’s left to the forecaster’s discretion. If the scope of the forecast includes Chicago’s distant suburbs in Illinois, Indiana, and Wisconsin, “near the lake” could be 10 or 15 miles inland. In a local forecast, the area could be just a mile or so, when the temperatures at Meigs Field and the Loop differ considerably from Midway (8 miles inland) and O’Hare (12 miles).
One (but not the only) insight would be to look at forecast winds: if winds are east or northeast at 10 m.p.h. or more, the lake effect will reach well inland. If the afternoon winds forecast has a westerly component, the lake breeze will struggle for each block of westward progress.
———-
Tom Skilling is chief meteorologist at WGN-TV. His forecasts can be seen Monday through Friday on WGN News at noon and 9 p.m.
Send your questions to:
ASK TOM WHY, 2501 Bradley Place, Chicago, IL 60618
e-mail: asktomwhy@tribune.com
