The National Weather Service says that overnight lows tonight will be quite cold, dropping into the mid to upper 20s. Some relief is on the way, however, as winds will shift to the south overnight. Combined with plenty of sunshine expected Tuesday, temperatures are forecast to rebound, returning to near-normal levels in the upper 40s to lower 50s.
Wednesday will be even a few degrees warmer than Tuesday. Breezy conditions are expected to develop Tuesday and continue into Wednesday ahead of the next weather system. Forecast models indicate a system moving in from the upper Mississippi Valley, bringing a cold front through the area late Tuesday night into Wednesday. Winds will come from the south to southwest at 10 to 20 mph, with gusts up to 25 to 30 mph Tuesday and Tuesday night. Winds will shift to the northwest behind the front on Wednesday and gradually decrease later in the day. There is a slight chance for a few light rain showers late Tuesday night into Wednesday morning, mainly across southwest Indiana and northwest Kentucky, while most of Southern Illinois should remain dry.
Colder air will move in behind the system, with another weak cold front expected to cross the region Thursday into Friday, bringing in even colder conditions. Looking ahead to the weekend, strong high pressure will build in from the northwest, making Friday night and Saturday the coldest stretch of the week. Wind chills could drop as low as -5 to +10 degrees Friday night into Saturday morning. Overnight lows Friday are expected to range from about 8 degrees in the north to 18 degrees in the south, with highs Saturday mostly in the 20s to near 30 degrees.