A major storm is expected to hit the Santa Barbara, San Luis Obispo, Ventura and Los Angeles counties starting Wednesday, with the greatest impacts expected Thursday. According to the National Weather Service, light rain will begin in Santa Barbara County around 12 a.m. Wednesday, while heavy rain is expected around noon on Thursday. There is a high risk of road flooding and a moderate risk for burn scar debris flows between Thursday at noon and Friday at 6 a.m. Residents should stay off the roads on Thursday, the NWS said. The rain is expected to end by 6 p.m. Friday.