The National Weather Service in Chicago has issued a * Flash Flood Warning for... Southeastern Cook County in northeastern Illinois... Northern Lake County in northwestern Indiana... * Until 1045 PM CDT. * At 452 PM CDT, Doppler radar indicated thunderstorms producing heavy rain across the warned area. Up to two inches of rain have been reported in under an hour. Flash flooding is ongoing or expected to begin shortly. HAZARD...Flash flooding caused by thunderstorms. SOURCE...Radar indicated. IMPACT...Flooding of small creeks and streams, urban areas, highways, streets and underpasses as well as other drainage and low lying areas. * Some locations that will experience flooding include... Hammond, Gary, Calumet City, Portage, Merrillville, Chicago Heights, East Chicago, Schererville, Hobart, Lansing, Highland, Munster, Dolton, Griffith, Lake Station, Steger, Glenwood, Whiting, Burnham and South Holland.