Chicago area is positioned on the northern edge of severe storm risk Thursday

The National Storm Prediction Center has determined a broad area from the Gulf of Mexico north to the Ohio River Valley will be under a risk for severe storms and tornadoes Thursday. The Enhanced and Slight Risk portion of the outlook covers central and southern Illinois and Indiana with the Chicago area partially under the Marginal Risk of severe storms.

The greatest risk of severe storms in Illinois and Indiana will exist later this morning and afternoon as a center of northeastward-moving low pressure and its associated warm and cold fronts cross the Mississippi River in western Illinois and track east-northeast, triggering renewed lines and bands of severe thunderstorms.

An Enhanced Risk (tan-shaded area on highlighted map) depicts a 30 % chance of severe storms within 25 miles of a given location, while a Slight Risk (yellow-shaded area) depicts a 15% chance of severe storms within 25 miles of a given location, and a Marginal Risk (green-shaded area) depicts a 5% chance of severe storms within 25 miles of a given location.

Current weather radar mosaic…

Central Great Lakes sector loop