Marginal risk of severe storms in Chicago area this evening

CHICAGO — With a hot increasingly more humid and unstable air mass pushing out of the plains into the western Great Lakes, there will be a Marginal Risk of severe thunderstorms (green-shaded area on the headlined map depicting a 5 percent chance of severe storms within 25 miles of a given location) reaching the Chicago area this Friday evening/tonight.

 

Hot, humid, high-dew point air will be in place this afternoon over the central and northern plains into the western Great Lakes while an upper-level impulse of colder air will sweep east over the top destabilizing the area this afternoon during the peak-heating portion of the day, triggering the development of strong to severe thunderstorms with damaging winds and large hail possible over western Wisconsin and Iowa (yellow-shaded area on the headlined map depicting a 15 percent chance of severe storms within 25 miles of a given location).

This upper-level short-wave will track on east, spreading thunderstorms across northern Illinois/Wisconsin this evening. As the storms reach western portions of the Chicago area, they should be weakening somewhat with the loss of the daytime heating.