The Coldest So Far This Season

A sprawling area of Canadian high pressure centered over North Dakota has cleared the skies over northern Illinois.  Temperatures have tumbled into the 40's as of 9 pm and will continue to drop into the middle 30's by late tonight.. There are frost advisories after midnight to the north and west of Rockford, and there could be some patchy frost in favored low lying areas over northern Illinois.  On Thursday skies will be sunny, but it will be chilly with highs struggling to reach 60 degrees by mid afternoon as the high moves across Minnesota into central Wisconsin by Thursday evening.  Skies will be clear again on Thursday night, and with light winds, good radiational cooling will allow temperatures to reach the middle 30's again producing some scattered frost in rural areas.  By early Friday the core of the high pressure will be located over Michigan, and winds will become southeasterly, and by Saturday, southerly winds will slowly start to warm the chilled mid west back up into the 60's.  Moisture will spread northward into the the area by Sunday.  Scattered showers and thunderstorms will be affecting the area off and on from Sunday through next Wednesday along with seasonal temperatures in the 70's.