( CNN ) -- A strengthening El Nino is expected to bring torrential rain Thursday to parts of Southern California , including Los Angeles , and authorities warned of possibly severe mudslides in areas denuded by forest fires . The storm could dump 8 inches to 10 inches of rain on the Los Angeles area and higher amounts in the foothills , the National Weather Service said . Late Tuesday , Los Angeles Mayor Antonio Villaraigosa -- expecting a dangerous storm Wednesday -- urged hundreds of Californians to leave their homes . A torrential rainfall Tuesday unleashed flooding and spawned a rare tornado warning . Are you being affected by the storms ? Send your images , video . There has been some resistance to the advice , a detective with the Los Angeles Police Department said . The detective , who would n't give her entire name , said she did n't know how many people decided to leave . Flash flooding on California golf course . There was heavy rain Wednesday in San Francisco and Sacramento , California , but Los Angeles had little precipitation as of about noon . Driving by homes , businesses under water . A warm ocean current from the South Pacific is responsible for this week 's storms , said CNN meteorologist Chad Myers . With little vegetation to help contain the water , the vast expanses in southern California that were hit by wildfires late last summer are causing concern for officials . The largest of the fires -- known as the Station Fire -- charred 250 square miles of land last summer north and east of Los Angeles . `` If you are lower in elevation than where a fire happened earlier this year , you need to be very , very cautious , '' Myers said . Forecasters said several feet of snow would fall in the higher elevations of the Sierra Nevada through the rest of this week , as low pressure systems continue moving into the area .
El Nino expected to bring torrential rain Thursday to parts of Southern California . Authorities warned of possibly severe mudslides in areas denuded by forest fires . Warm ocean current from the South Pacific responsible for storm .