Heavy Rainfall Could Lead to Flash Flooding Across the Midwest/Great Lakes

A Flash Flood Watch has been issued for Green, Rock and Walworth counties in southern Wisconsin, and for Stephenson and Jo Daviess counties in northwest Illinois beginning early Tuesday morning and lasting through Wednesday morning. Several more inches of rain are possible from the Plains into the Midwest.

A strong ridge of high pressure over the Gulf states and strong low pressure over the Rockies

will continue to pull high amounts of moisture into the Plains and Midwest Monday evening. A couple severe thunderstorms have already developed over south-central Nebraska, while a line of showers extends north along a cold front. 

Ongoing thunderstorms will be likely from Iowa to southern and central Wisconsin for the start of Tuesday. A few storms could slide a little further south into northern Illinois during the early afternoon. As the cold front moves into the Midwest Tuesday evening, thunderstorms will become a little more widespread over Wisconsin before sinking into northern Illinois by Wednesday morning. Another 1-3 inches of rain will be possible for southern and central Wisconsin, with lesser amounts to the south over northern Illinois. The chance for rain will increase, however, locally Wednesday as low pressure moves through.