Thunderstorms will last through the evening, and then on Sunday, hot temperatures will return, with the heat index between 100 and 105 degrees. A flood watch is in effect as a threat of severe storms is expected by the afternoon for the Chicago area.

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.