LOS ANGELES (AP) — An unusually strong storm system called an atmospheric river was dousing Southern California on Saturday, prompting flood warnings in areas of coastal Los Angeles County that recently were ravaged by wildfire.

The National Weather Service in Los Angles and Oxnard reported heavy rainfall Saturday at rates as heavy as an inch (2.5 centimeters) per hour in coastal areas that are prone to flash flooding.

On Friday, more than four inches of rain fell over coastal Santa Barbara County as the storm approached Los Angeles, as the National Weather Service urged people to stay indoors amid heavy winds.

The long plume of tropical moisture that formed over the Pacific Ocean began drenching the San Francisco Bay Area on Wednesday and unleashed widespread rain over Southern California on Friday and Saturday. More than a foot of snow was predicted for parts of the Sierra Nevada.

Flood warnings extended from the Ventura County coast, through Malibu and into the City of Los Angeles.

“Due to the potential for debris flows, an Evacuation Warning remains in effect within and around all recent burn scar areas, and select vulnerable properties remain under Evacuation Orders,” Los Angeles Mayor Karen Bass said in a Saturday-morning social media post on X.

Evacuation orders, which are mandatory, were issued for specific high-risk properties in the Palisades and Eaton fire burn areas from Friday evening to Sunday morning. Law enforcement personnel were going to select properties in those areas to urge people to leave, Bass indicated.