Snow squalls were possible Wednesday afternoon and evening, which included higher winds and plunging temperatures.
Squalls can create slick spots, reduce visibility and put a coating of snow on the ground.
The squalls only lasted 30 minutes to an hour in any one spot. Passing lighter snow is possible in the evening.
Squalls were possible from 3 to 6 p.m. for much of the Chicago area and from 4 to 7 p.m. for the south suburbs and northwest Indiana, ABC7 Chicago meteorologist Larry Mowry said earlier Wednesday.
As of 6:35 p.m. Wednesday, 10,504 ComEd customers were without power in northern Illinois, the company said. As of 6:40 p.m. Wednesday, 4,845 NIPSCO customers were without power in Northwest Indiana, the company said.
A National Weather Service Wind Advisory went into effect at 2 p.m., and was scheduled to last until midnight.
Thursday is forecast to be very cold, with wind chills from -5 to -10 during the morning.