Chicago residents faced a volatile weather day on Thursday as a line of thunderstorms moved across northern Illinois. The National Weather Service has issued a flood watch for large parts of the Chicago metropolitan area.A flood watch remains in effect across parts of northern Illinois as thunderstorms move through the Chicago area. Image for representational purposes. (Unsplash )The flood watch covers a broad swath of northern Illinois, including Boone, Cook, DeKalb, DuPage, Grundy, Kane, Kankakee, Kendall, La Salle, Lake, Lee, McHenry, Ogle, Will, Winnebago and surrounding counties.According to the ATC Alerts, flights have also been halted at Chicago O’Hare International Airport due to thunderstorms in the area.(This is a developing story)