iReport — Lightning hits the Willis Tower - June 30, 2011 Chicago - Strong thunderstorms dropped large hail — some golf ball-sized -- throughout the Chicago area, knocking out power to thousands of Commonwealth Edison customers and causing transportation problems Thursday night. A severe thunderstorm watch has been issued for the Chicago area until midnight. The counties included in the watch are Cook, DuPage, Lake, Will, Kankakee and Iroquois. A severe thunderstorm warning issued for southern central Cook County and Will County expired at 10:30 p.m. Hail was reported in the Chicago area including golf ball-sized hail in East Garfield Park and hail the size of a nickel to a quarter in diameter at the corner of Lincoln and Cullom avenues on the North Side. As of 9:30 p.m., 50,000 ComEd customers were without electricity in the Chicago area. Half of the outages were in the south suburbs and the remainder were split roughly between the north suburbs and Chicago.