A Marginal Risk of severe thunderstorms across the Chicago area Saturday

The National Storm Prediction Center Severe Weather Outlook for Saturday includes the Chicago area in a Marginal Risk of severe thunderstorms today (green-shaded area on the highlighted map depicting a 5% chance of severe storms within 25 miles of given location). The main risks will be for damaging winds and localized flood-producing downpours. The National Weather Prediction Center has outlooked our area for a Marginal Risk of Excessive Rainfall and the possibility of localized flooding (see green-shaded area on the map below).

Warm moist air will persist over much of Illinois into western Indiana today with a semi-stationary weak cold front oriented east-west from southern Lower Michigan along the Illinois-Wisconsin border into southern Iowa. A slow-moving upper-level disturbance will move east out of Iowa across northern Illinois this afternoon and on east this evening.

As a result showers and embedded thunderstorms will be ongoing this morning, letting up a bit later in the morning, then redeveloping again this afternoon. The best chance of severe storms will be this afternoon, when the upper-disturbance combines with peak afternoon heating to create the most unstable atmospheric conditions. The main storm threat should move on east and south later this afternoon/evening.

Excessive Rainfall for Saturday/Saturday night…

Day 1 Excessive Rainfall Forecast