Monday...Just Like Mid-summer...Much Cooler for the Rest of the Week

Sprawling high pressure will provide warm conditions under sunny skies on Monday.  Temperatures will reach the middle 80's, and it will become breezy in the afternoon as a vigorous area of low pressure advances along the Canadian border just north of Minnesota.  A strong cold front will trail that low as it progresses eastward, and it will sweep across the Stateline on Monday night along with a slight chance of showers and thunderstorms. In fact, no rain may materialize at all, because the system is moisture starved with the Gulf of Mexico cut off from the Midwest.  It will be considerably cooler on Tuesday behind the cold front with afternoon highs in the low 70's under mostly sunny skies. A secondary re-enforcing cold front will move through northern Illinois by daybreak on Wednesday.  Unseasonably cool air will follow in behind that front from northern Canada. The high temperatures will be in the 60's for the rest of the week through Saturday, and the lows at night will be in the 40's, with the exception of Thursday night, when it could drop into the upper 30's.  Skies will be clear from Friday through Sunday as the huge Canadian high pressure moves across the Great Lakes into New England.