A severe thunder storm watch has been issued for the Chicago area until 9 p.m. Thursday.
Storms are expected to move from the northwest into Cook County between 5 p.m. and 7 p.m., the National Weather Service said.
Damaging winds of 60 mph and large hail up to quarter size are possible, the weather service said. Storms will be strongest north of Interstate 88.
Additional storms are possible late Thursday night into early Friday, the weather service said.
Friday’s forecast is a 30 percent chance of rain and thunderstorms in Cook County with highs in the lower 90s.