The Weather Prediction Center (WPC) has the Chicago area and all of Northern Illinois in a level two of four or a slight risk for potentially excessive rainfall on Thursday that could cause localized flooding.
Excessive rainfall outlook 7AM Thursday through 7AM Friday
Chicago’s rain and precipitation chances
It’s been dry: Monday marked the 6th consecutive day without measurable precipitation
That is likely to change late Wednesday night into Thursday when showers and thunderstorms become likely
Model snapshot guidance beginning Wednesday night:
Potential for soaking rains across the Chicago area later this week…
Total rainfall through 7PM Saturday.
Source: Weather Prediction Center