Heavy rain, flash flooding possible in Chicago area overnight

Heavy rain and thunderstorms could bring flash flooding to the Chicago area overnight Sunday, with forecasters most concerned about the period from about 10 or 11 p.m. through early Monday. A flood watch issued Sunday afternoon remains in effect until 7 a.m. Monday, according to the National Weather Service. Showers and thunderstorms were developing across northwest Illinois and moving into the area Sunday evening, said Mike Bardou, a meteorologist with the National Weather Service. The storms…