There does remain a risk for a few stronger thunderstorms Thursday night, but that risk appears to be favored more towards eastern Iowa and southwest Wisconsin. A warm front currently is draped across northern Illinois with temperatures warming into the 70s south of the front, but remaining in the 50s north of the front. As of 7:30pm, the temperature in Rockford has cooled back down to 55 degrees after warming to 68 degrees at 5pm. Dense fog and low clouds were also found across much of far northern Illinois and southern Wisconsin reducing visibility down to only a few hundred feet in some locations.
The warm front won’t lift too much further north and, in fact, could actually sink a bit further to the south through Thursday evening. Fog and low clouds will be common areas north of the boundary but should begin to clear once the low and cold front passes through.
Thunderstorms have been ongoing in a line from southwest to northeast from Iowa to Wisconsin, along and behind the cold front. There are currently no severe thunderstorm warnings at the moment but a few of the stronger storms in Iowa were capable of producing nickel sized hail and wind gusts to 30 mph. The highest risk for any stronger storms will likely remain focused from eastern Iowa, up through southwest Wisconsin with the greatest risk being hail. Storms will continue to move northeast into Wisconsin through about 10pm/11pm, and then begin to shift east with the cold front. Storms will move through the Stateline during the night (after 11pm) with showers lasting through Friday morning.
Heavy rainfall and localized flash flooding will also be possible, especially with the northeast movement of the storms into Wisconsin. Rainfall amounts of 1-2 inches will be possible by Friday morning, specifically over southwest Wisconsin and northwest Illinois. Overall, rainfall totals of half an inch up to an inch are possible.