Flood Watch issued for most of Chicagoland until 7 p.m. Saturday. Heavy rain is possible tonight and tomorrow. 3:18 p.m. - Flood Warning issued for DuPage, Cook Counties until 5:30 p.m.Ground delays issued at O'Hare, Midway airports due to storms. Average delay is 75 minutes, according to the FAA.

The storms can produce damaging winds and cause flooding, as one to three inches of rain are expected in some areas.

Torrential rains nearing 5 inches in just a few hours led to flash flooding across parts of Chicago on Friday afternoon, snarling both traffic on the ground and in the air.