CHICAGO — The National Weather Prediction Center predicts a slight risk of excessive rainfall over much of Illinois and Iowa as well as northwest Indiana and southern Wisconsin, including the entire Chicago area, Monday evening into the overnight hours. The National Storm Prediction Center has most of our area included in a marginal risk for severe storms a greater risk centered over the lower Ohio Valley.
Heavy localized flood-producing downpours of 1 to 2-inches or more are expected to accompany showers and embedded thunderstorms spreading from southwest to northeast across the Chicago area today. The severe weather threat of damaging winds and even the possibility of a tornado or two will likely peak this afternoon/evening in the proximity of a warm front pushing north through northern Illinois.
Aided by an extensive low pressure trough aloft, a center of low pressure will move east through northern Missouri and southern Iowa today, passing over northern Illinois tonight and on northeast into Lower Michigan Tuesday. A tongue of warm moist unstable air out of the Gulf of Mexico will flow into Illinois and western Indiana lifted over the warm front ahead of the approaching low pressure system.
A slow improvement from the west should occur Tuesday, as the low pressure pulls off to the northeast.
Severe Weather Outlook Map for Monday/Monday night...
Current Regional Weather Radar Mosaic...
The National Weather Service tweeted that there will be very dangerous swimming conditions through Wednesday on Lake Michigan.