The worst storm in a series of storms has come and gone without serious consequences for California, but the El Nino-driven weather was still causing problems around the state.

That includes dropping temperatures, rising waves and pernicious winds predicted for Thursday.

Mountain areas were warned that blizzard conditions with wind gusts reaching 90 kilometres per hour were possible above 1,220 metres, including the heavily traveled Grapevine section of Interstate 5.

Damaging surf of three to nearly five metres were possible in Southern California and waves from five to seven metrescould hit the Central Coast through Thursday night, the National Weather Service said.

In San Diego County, winds were serious enough to bring a brief tornado warning Wednesday.

And rains hit several areas hard late Wednesday night. Voluntary evacuation advisories in some burn areas in danger of mudslides were cancelled. But authorities evacuated 10 mobile homes in the Newhall area northwest of Los Angeles as watery mud flowed into the streets from hillsides burned bare in a June fire, Los Angeles County officials said. No injuries or serious damages were reported.

Driving rain inundated the San Francisco Bay Area during the morning commute, causing nearly two dozen crashes, toppling trees and flooding streets and streams. (Mike Blake/Reuters)

Northeast of Los Angeles in Monrovia, Wayne Socha used a sledgehammer to knock a hole in a cement wall in his backyard to let built up mud and debris flow through. A wildfire two years ago stripped away vegetation and loosened soil, and he feared the strong storms could bring it all down.

"It looked like Niagara Falls," Socha said. "It was quickly building up behind the house and I knew it could come right inside."

At the foot of the San Gabriel Mountains, Monrovia officials dispatched crews with sandbags to help protect Socha's neighborhood from landslides. That eased his mind somewhat, but he said he and his wife were vigilantly watching forecasts of more rain.

"We're amateur meteorologists now," he said.

Well over two inches of rain fell on several mountain areas of Southern California on Wednesday, including 3.5 inches at the San Gabriel Dam in the Angeles National Forest.

Driving rain also inundated the San Francisco Bay Area, causing nearly two dozen crashes among commuters, toppling trees and flooding streets and streams. Officials shut down the city's iconic cable cars for much of Wednesday.

The current storm could dump as much as eight centimetres of rain in coastal and valley areas and up to 10 centimetres at higher elevations. (Mike Blake/Reuters)

Another less-powerful El Nino storm was right behind and expected to reach land Thursday.

Despite the potential for problems, the wet weather in California was welcome news for the state suffering from a severe drought. But officials warned residents against abandoning conservation efforts and reverting to wasteful water-use habits.

The current El Nino system — a natural warming of the central and eastern Pacific Ocean that interacts with the atmosphere and changes weather worldwide — has tied a system in 1997-1998 as the strongest on record.