The National Weather Service in Chicago has issued a * Flash Flood Warning for red-shaded counties on headlined map... Winnebago County in north central Illinois... Western McHenry County in northeastern Illinois... Boone County in north central Illinois... * Until 815 PM CDT. * At 421 PM CDT, Doppler radar indicated thunderstorms producing very heavy rain across the warned area. Up to two to three inches of rain have already fallen, with locally higher amounts over three inches in northern Boone County. Additional thunderstorms were developing across the warned area. 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... Rockford, Beloit, Belvidere, Woodstock, Loves Park, Machesney Park, Harvard, South Beloit, Rockton, Marengo, Rockford Airport, Huntley, Roscoe, Poplar Grove, Cherry Valley, Winnebago, Pecatonica, Sharon, Durand and Capron. PRECAUTIONARY/PREPAREDNESS ACTIONS... Excessive runoff from heavy rainfall will cause flooding of small creeks and streams, urban areas, highways, streets and underpasses, country roads, farmland, as well as other drainage areas and low lying spots. Turn around, don`t drown when encountering flooded roads. Most flood deaths occur in vehicles.