Decreasing Clouds and Colder Tonight

The Stateline will see decreasing clouds tonight, and temperatures will fall to the middle single digits toward dawn with light northerly winds as a weak ridge of high pressure takes control of our weather.  The clouds will increase again on Sunday as the next weather system appoaches Illinois from the plains states.  It will be chilly, though, with a high only around 20 degrees.  The wind with increase from the south at 10 to 15 mph tomorrow night as warmer air returns northward ahead of the advancing system, and there could be some light snow after midnight. It will be windy on Monday as the system continues to work it's way eastward into the midwest.  It looks like a snowy day with some accumultation likely.  Early estimates indicate at least 2" of snow, and possibly up to 4" in spots.  There will be a lot of warm air drawn across northern Illinois with this system, and there is a slight possiblilty that there may even be some freezing rain mixed with the snow on Monday, depending on the strength of the warm air advection, and the path of the surface low.  If it passes to our south, all of the precipitation will be in the form of snow.  If it takes a track right across northern Illinois, or father north across southern Wisconsin, we could see some freezing rain and sleet mixed with snow on Monday.  There may be a period of freezing drizzle on Monday evening, and then flurries overnight persisting into Tuesday.  The Stateline will get a brief shot of modified arctic air on Wednesday with highs dropping back to the middle teens.  A new cold front will mark the leading edge of re-enforcing arctic air Thursday as the core of the coldest air of the season drops out of Canada into Montana by 6 am on Thursday morning.  By Friday morning it will be located over eastern Kansas, and by Saturday morning over Illinois.  If this high pressure moves out of Canada, as it is currently expected to do, and across the nations heartland,  it will bring the Stateline the coldest weather to northern Illinois so far this season... It is possible that high tempertures on Friday may have a tough time getting much above zero, and low temperatures on Saturday morning will be around -10.  Not all of the meteorological models agree with this senario, however.  One takes the brunt of the cold air eastward across Canada, and if that happens, it will not be nearly so cold in the Stateline.
By Meteorologist
Eric Nefstead