While there will be a few scattered light showers mainly across southern portions of the Chicago area this Monday morning, there is a threat of stronger, potentially severe thunderstorms storms developing and moving through northeast Illinois into northwest Indiana later this afternoon and evening. The National Storm Prediction Center has the entire Chicago area under a Marginal to Slight Risk of severe storms (green-shaded and yellow-shaded area on the headlined map) the main risks being damaging winds and large hail.
A cold front will be approaching from the west, supported by an upper-level disturbance (short wave) that will trigger a band of strong to severe thunderstorms ahead of the system as it moves east. The front should pass through our area later tonight, with the leading edge of the storms approaching western portions of our area this afternoon and eventually moving off to the east later this evening. A stronger Enhanced Risk of severe storms (tan-shaded area on the headlined map) exists downstate from Missouri through southern portions of Illinois and Indiana.
The latest Regional Weather Radar Mosaic is displayed below along with a chart depicting storm timing prepared by the Chicago National Weather Service.