Columbus Day will be cooler than this past weekend, but nothing like the cold expected later this week. Today’s slightly below-normal highs will probably be the warmest readings Chicagoans will experience until perhaps the middle of next week. The upper-air pattern is forecast to change drastically in the next 36 hours.
Presently, winds at 30,000 feet over Chicago are southwest around 40 m.p.h. with the 100 m.p.h.-plus core of the jet stream situated along the U.S./Canada border. By Wednesday, the jet stream flow will shift north-south with a core of 150 m.p.h.-plus winds just to the west through the Dakotas and western Iowa. An Arctic-source high pressure air mass will be steered directly south through Canada into the western Great Lakes and Midwest. By Thursday, there’s a good chance snow will blanket northern Wisconsin and upper Michigan, while the Chicago area is hit with record cold (highs in the 30s Thursday) and snow flurries.
--By Paul Dailey, WGN Weather Center Meteorologist
WGN-TV Chief Meteorologist Tom Skilling and the WGN Weather Center staff provide daily coverage of weather in the Chicago area.
