Chicago weather: Another steamy day with severe storms possible

Chicago weather: Wednesday morning forecast

FOX 32's Mike Caplan breaks down today's weather outlook.

CHICAGO - Chicago has now had 17 days of 90° temperatures this year. That’s equal to the normal in an entire year. Today will be day 18. Even still, it’s a long way off from even breaking into the top ten for 90s in a year which starts at 32. 1988 is the granddaddy of them all with a record of 47 days of 90°+. 

Ozone will build up in the sunlight and heat just like Tuesday-warranting the extension of the air quality alert through the night. The next question deals with the risk of thunderstorms this afternoon and evening.

Most of today will be partly sunny, hot and humid. High temperatures will likely be a couple of degrees higher than yesterday‘s 91. The attendant increase in humidity could push the heat index close to 100°.

Storm potential

Dig deeper:

By mid to late afternoon, thunderstorms will be assembling over Iowa and Wisconsin heading to the east. There remains quite a bit of uncertainty as to how strong any of these storms will be when they move into our area. Several computer models show a split developing with one part of the line going towards central Illinois and the other area largely in southern Wisconsin. 

I think we do see thunderstorms and there would be a possibility that one or two could be strong to severe. Damaging straight-line winds are possible with brief downpours. Flooding is unlikely due to the progressive movement of the line of storms through our area.

Future forecast

What's next:

Tomorrow will be much cooler. In fact, it could be dramatically cooler with afternoon temperatures barely in the 70s across much of Chicagoland. 

Southern sections will likely still get into the low 80s with falling temperatures in the afternoon. Rainfall prospects look bleak in my opinion. 

Friday should be a beautiful day with plenty of sunshine and high temperatures rising into the lower 80s. 

Over the weekend, showers and thunderstorms look quite likely on Saturday with highs in the low to mid 80s. I’m leaning heavily on the European model for my Sunday forecast, which would keep things dry and warm with highs in the mid 80s. 

Hot weather returns next week, certainly by Tuesday when 90-degree temperatures become likely. There could be some scattered thunderstorms as the heat returns.