UPDATE: The National Weather Service in Chicago has issued a Flood Advisory until 6:15 p.m. Tuesday evening.

The National Weather Service said a severe thunderstorm was located moving southeast over Burbank. Quarter-sized hail and 70 mph wind gusts are possible.

Original story:

CHICAGO — Sun and clouds Tuesday with a chance of isolated showers and thunderstorms. Air quality is in the Good category. Winds: WSW/NNE 5-15 mph. High 85/82 lakeside.

Increasing clouds tonighy. Rain/t-storms return overnight. Winds: ENE 10-15 mph. Low 66.

Tuesday, July 11
HIGH: 88 LOW: 67
Increasing cloudiness, breezy, quite warm, more humid. Scattered showers and thunderstorms develop over 40% of the metro area. High 89, but temperatures falling into the 70s by late afternoon, especially along the lake. Southwest winds shift to the north/northeast 6-15 mph. High: 88.
Tuesday Night
Cloudy, humid with scattered showers and thunderstorms impacting at least half the metro area by daybreak Wednesday. Some storms could be strong with locally heavy downpours. Low: 67.

Wednesday, July 12
HIGH: 76 LOW: 67
Considerable cloudiness, cooler, but remaining humid. Clusters of showers and thunderstorms, the heaviest is capable of gusty winds and downpours. Current forecasts project the best chances for severe storms across the southernmost sections of the viewing area. High: 76.

Extended outlook calls for drying out and warming up as we get into Thu with temps back in the 80s with partly sunny skies and a slight chance of a t’storm. Friday we’re see more warmth with highs back towards upper 80s to low 90s with a slight chance of showers/t’storms. The weekend will see temps in the 80s and a slight chance of showers/t’storms each afternoon. 

Full forecast details and more at the WGN Weather Center blog