A strong cold front will trek across the country, reaching northern Illinois and southern Wisconsin Friday morning. Ahead of the front, temperatures will warm into the upper 60s and low 70s Thursday afternoon and briefly Friday morning.
Showers and isolated thunderstorms will be likely, especially Thursday night and Friday morning. The cold front will pass through the Stateline before Noon, shifting winds around to the west for the remainder of the afternoon. Wind-driven showers will continue into the afternoon but should come to an end a little after sunset.
A cold air mass will filter in behind the front with temperatures falling from the low to mid 60s early Friday morning, down into the 50s Friday afternoon and then into the 40s by Friday evening. Overnight lows will dip into the low to mid 30s area wide, with some locations possibly reaching the freezing mark by Saturday morning. Winds will remain strong through the morning and this will push wind chills down into the 20s! We likely won’t see frost Friday night because of the cloud cover and blustery winds, and even Saturday night will see some cloud cover. Winds should settle a little more Sunday night, however, and this could prove to be a better chance for frost development.
Heading out the door Friday you’ll want to dress for what the weather will be like during the afternoon, and not what you’ll feel Friday morning. It’ll be cool in the morning, but colder by Friday late afternoon.