Risk of severe thunderstorms across the Chicago area later Wednesday afternoon/evening
The National Storm Prediction Center has issued a severe weather outlook (see highlighted map) that has the Chicago area under a risk of severe storms later Wednesday afternoon into the evening hours. The greatest threat will be across westernmost counties under a Slight Risk (yellow-shaded area depicting a 15 % chance of severe storms within 25 miles of a given location) with the remainder of our area under a Marginal Risk (green-shaded area depicting a 5% risk of severe storms within 25 miles of a given location).
Warm moist low-level winds gusting in excess of 40 miles per hour will be overlain by a 80 to 90 mile-per-hour jet stream aloft that will further destabilize the atmosphere during the peak-heating hours, generating lines of strong thunderstorms that should maintain their strength as they move east-northeast into northern Illinois, southern Wisconsin and northwest Indiana. Greatest risk with the storms in our area will be damaging winds along with large hail.