A Flash Flood Warning is in effect for the Chicago area as severe storms roll through, which also caused problems at O'Hare and Midway airports.

As of 12:30 p.m., heavy rain had already started to fall in some parts. A flash flood warning was in effect for DuPage and Cook County, the NWS said, with reports of "totally submerged viaducts and underpasses in the city of Chicago."

Since January, more than 3,100 flash flood warnings have been issued nationwide — the highest year-to-date total since tracking began for alerts in 1986.