About 6:50 p.m. a tornado warning was issued for southeastern Cook County, northern Lake County in Indiana as well as northwestern Porter County, according to the National Weather Service.
The warning was canceled soon after 7:15 p.m. in most areas nearest Chicago as the storm moved eastward.
Earlier, at about 6:24 p.m., officials said radar indicated that a severe thunderstorm capable of producing a tornado was located near Calumet City and moving east at 20 mph, according the National Weather Service.
A meteorologist said an unconfirmed report indicated that a tornado was spotted on the ground near Calumet City. A Calumet City police dispather said the report of a tornado on the ground was unfounded, but there were reports of funnel clouds.
The funnel clouds were spotted in the air above the Cook County-Lake County, Ind., border near the area of Calumet City and Hammond, according to the weather service and Calumet City police.