Severe Storms Possible, Oppressive Humidity To Hit Chicago Area

ILLINOIS — Strong to severe storms are possible on Wednesday, as afternoon heat index values of near 100 degrees are possible, according to the National Weather Service.

However, before storms approach the area on Wednesday, an air quality alert is in effect for the Chicago metro area through Tuesday evening. The weather service said the air quality alert was issued due to unhealthy ozone levels and some lingering effects of Canadian wildfire smoke.

Heat and humidity will continue to build through mid-week, and storms are expected Wednesday afternoon into Thursday; and some storms on Wednesday evening could be strong, the weather service said.

The high for Wednesday is 92 degrees, and the strongest storms could bring damaging winds and flash flooding to the area, according to the weather service.

"There is still uncertainty in the exact coverage of storms and where the greatest threat for severe storms and flash flooding will end up being, so stay tuned for additional forecast updates," the weather service said on its Facebook.

Chances of storms continue on Thursday, and while Friday should be dry, storms could return on Saturday.

The weather service said there will be "periodic bouts" of rain and storms Saturday through Monday. Any of these storms could produce heavy rain and flooding.

Here is a more detailed look at the daily forecast, per the weather service:

TUESDAY NIGHT: Partly cloudy, with a low around 73. South wind around 5 mph becoming calm in the evening.

WEDNESDAY: A 30 percent chance of showers and thunderstorms after 1 p.m. Mostly sunny, with a high near 91. Heat index values as high as 100. Southwest wind 5 to 15 mph, with gusts as high as 20 mph.

WEDNESDAY NIGHT: Showers and thunderstorms likely. Mostly cloudy, with a low around 69. Southwest wind 5 to 10 mph, with gusts as high as 15 mph. Chance of precipitation is 60 percent.

THURSDAY: A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 78. West wind 5 to 10 mph becoming north northeast in the afternoon. Winds could gust as high as 20 mph.

THURSDAY NIGHT: Mostly cloudy, with a low around 61.

FRIDAY: Mostly sunny, with a high near 80.

FRIDAY NIGHT: Partly cloudy, with a low around 65.