A series of strong thunderstorms may dump more heavy rainfall over the Stateline, resulting in flash flooding in some areas. The greatest risk for flash flooding looks to line up in southern Wisconsin, though areas near and north of US 20 are at a lower risk.
Flash flooding is already ongoing around Dubuque, and from Marengo southeast into Chicago, as well as from Lake Geneva, WI to Kenosha, WI. Some of these areas have already picked up over 4" of rainfall.
The worst of the rainfall looks to move through between 2 AM and 5 AM. The risk for flash flooding will slowly shift north into southern Wisconsin, but a few more inches of rain may fall into extreme northern Illinois. This may include Freeport and Rockford.
When flash flooding occurs, avoid any road with water covering it. Turn around, don't drown! It does not take much standing or flowing water to strand you and your car, whether your car floats off the road or stalls out. Also be aware of small streams and rivers, which may flood quickly.
Use our Interactive Radar to track the storms into your area. The storms should settle down by early Wednesday; after that, extreme heat with heat index values in the 100's are possible.