Risk of strong to severe thunderstorms across Chicago area Wednesday
Update 1:15PM CDT…
The severe thunderstorm outlook has been adjusted for Wednesday/Wednesday night (see updated highlighted severe weather outlook map) with the area south and east of Chicago under a Slight Risk of severe storms and the remainder of the area under a Marginal Risk. Strong to isolated severe storms could move into our area from the west early Wednesday morning, weakening later in the morning. Then as a cold front moves through the area from the west new storms could develop later in the afternoon into the evening hours along and ahead of the frontal boundary – this is where the Slight Risk (yellow-shaded area) south and east of Chicago would most likely come into play.
All storms should move off to the east with the cold front later Wednesday evening/overnight.
The National Storm Prediction Center has positioned the Chicago area in a Marginal Risk (dark-green-shaded area on the highlighted map depicting a 5% chance of severe storms within 25 miles of a given location) Wednesday.
A greater Slight Risk of Severe storms (yellow-shaded area on the highlighted map depicting a 15% chance of severe storms within 25 miles of a given location) covers southern and central Illinois, reaching into the portion of our area south of Interstate-80.
The main risk with these storms will be damaging winds and large hail.
As low pressure and the associated cold front move east out of Iowa and Missouri later tonight and early Wednesday, a band of showers and strong to severe thunderstorms will develop and spread into western Illinois, reaching the Chicago area early Wednesday morning. These storms will weaken later in the morning, then possibly redevelop later in the afternoon/evening along and ahead of the cold front as it moves east through our area. Showers/storms should end from the west later Wednesday night, as the front moves off to the east.