With a northwest flow aloft steering Canadian-source air into the western Great Lakes and predominantly easterly surface winds, temperatures this week look to average a little below normal. High pressure will center over Lake Michigan Monday and then edge into the eastern Great Lakes later Tuesday, where it will hold until late week. Meanwhile, low pressure in the Northern Plains will move into the upper Mississippi Valley. For Chicago, sitting on the edge of these two weather regimes, this eastward movement will mean much more cloudiness and a chance of rain as early as late Tuesday.
If computer models prove correct, a very unusual low pressure circulation aloft could drift slowly southeast in the northwesterly flow, enhancing development of a broad moisture-laden low pressure surface system that could mean a 48-hour-plus period of showers and thunderstorms for northern Illinois next weekend.
HEAVY RAINS OVER SOUTHEAST U.S.
Pushed to the Gulf Coast by the strong northwest flow aloft, a stationary front oriented west-east through the Southeast will trigger heavy rains, well in excess of 2 inches, over most of the southeastern Gulf Coast states the first half of the week.
--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.
