FFWLOT The National Weather Service in Chicago has extended the * Flash Flood Warning for. Northwestern Boone County in north central Illinois. Central Winnebago County in north central Illinois. * Until midnight CDT tonight. * At 640 PM CDT, Doppler radar and automated rain gauges indicated thunderstorms producing heavy rain across the warned area. Between 2 and 4.5 inches of rain have fallen. Additional rainfall amounts of 1 to 3 inches are possible in the warned area. Flash flooding is ongoing. HAZARD. Significant flash flooding. SOURCE. Radar and automated gauges. IMPACT. Rapid-onset, significant flooding of creeks, streams, drainage ditches, low-lying areas, and poor drainage areas. Widespread street and underpass flooding. Possible flooding of structures. Possible flooding of highways. * Some locations that will experience flash flooding include. Rockford, Loves Park, Machesney Park, Roscoe, Rockton, Poplar Grove, Candlewick Lake, Pecatonica, Durand, Timberlane, Caledonia, Harrison and Shirland. Thunderstorms will continue to redevelop and produce periods of heavy rain across the warned area through this evening.