An overnight storm that dumped between 5 and 7 inches of rain on the Chicago area has forced the closure of several flooded expressways, ramps and roads, and blacked out several thousand utility customers.
Mark Ratzer, a meteorologist with the National Weather Service in Romeoville, says "extremely heavy rainfall" began shortly after midnight and in two hours dropped 5.53 inches at O'Hare International Airport. He says some Chicago suburbs reported upward of 7 inches of rain.
Ratzer says typically an "impressive storm" would deliver an inch-and-a-half of rain.
State Police officials say portions of several freeways and underpasses were underwater.
ComEd says about 86,000 utility customers were blacked out because of the storm.
More rain was expected Saturday morning as a storm in Iowa moved eastward toward Illinois.