Risk of severe thunderstorms begins across across far northern portion of the Chicago area later tonight/early Tuesday

The National Storm Prediction Center has outlooked the northernmost counties of the Chicago area bordering the Illinois-Wisconsin state line for a Marginal Risk of severe thunderstorms (dark-green-shaded area on the highlighted map depicting a 5% chance of severe storms within 25 miles of a given location) later tonight into Tuesday morning. The primary risk will be damaging winds and large hail.The Marginal Risk will then continue Wednesday over much Illinois into adjacent portions of Wisconsin and Indiana (see Tuesday/Wednesday outlook maps below).

A weakening frontal boundary in central Wisconsin will be reinforced by a cold front moving south out of Canada today with the front eventually becoming stationary, oriented west-east across southern Wisconsin. Thunderstorms are expected to develop along and ahead of this approaching frontal boundary later tonight, possibly drifting south into northern Illinois. With very warm, increasingly more humid air camped over our area, the threat of severe storms will continue Wednesday into Thursday – possibly beyond and will be monitored in the days ahead.

Severe weather outlook map for Tuesday/Tuesday night…

Severe weather outlook map for Wednesday/Wednesday night…