A strong late season storm system will develop Tuesday night and Wednesday morning east of the Rockies, quickly moving through the Plains Wednesday night, Upper Midwest Wednesday night and then Great Lakes by Thursday morning. Ahead of the low an unseasonably warm air mass will bring record breaking highs to many over the Midwest and Great Lakes, where temperatures locally are expected to reach the mid to upper 60s. Clouds will fill the skies throughout most of Wednesday and Wednesday night, leading to periodic light showers throughout the day.
Strong to even severe storms are possible over much of central Iowa as a strong, deepening low pressure system moves across the northwest part of the state. This also lines up with the highest instability and forcing aloft for severe thunderstorms Wednesday afternoon and evening.
As the low moves from NW Iowa Wednesday evening into the arrowhead of Minnesota early Thursday, it’ll pull a cold front through northern Illinois and southern Wisconsin around Midnight Wednesday. Ahead of the front a line of showers and thunderstorms will occur, moving through the area between roughly 9pm and Midnight. While thunderstorms are possible, the risk for any severe weather will remain relatively low locally.
Wind gusts ahead of the front could be as high as 50 mph at times, outside of any rain or thunder, and may produce sporadic wind damage or power outages. Gusty winds will continue into Thursday morning, but should come down a little in wind speeds throughout the day.