A third winter-like storm in a week brought rain and strong winds to much of Northern California and snow to the Sierra Nevada on Sunday.
Sheets of pouring rain made for treacherous driving, forcing the California Highway Patrol to handle several collisions in the Bay Area.
One person was injured in an accident on Highway 101 that blocked all lanes near San Rafael, north of San Francisco, the California Highway Patrol said.
Forecasters said showers and thunderstorms are expected throughout the day, and officials are reminding residents to drive slow, saying there is debris and flooding on the freeways.
Meanwhile, people lined up to grab sandbags in Palo Alto and others reported gusts of winds had downed trees in Menlo Park, East Palo Alto, Woodside, San Jose and elswhere. Blustery winds toppled a Christmas tree in Guerneville.
Mountain View police also took to Twitter to report downed power lines and power outages.
After a lull Saturday, the system moved into parched California overnight packing precipitation, strong winds, lightening and some hail.
The latest storm will dump slightly less rain in the state than the previous systems _ with the San Francisco Bay Area and the San Joaquin Valley expected to get up to about half an inch, National Weather Service meteorologist Nathan Owen said.
"We'll see a very similar storm to what we had the last round with less rain, but we're expecting a good bit of wind for this system," he said.
The National Weather Service issued a strong wind advisory for the Bay Area that will stay in effect through Sunday night, saying wind with gusts of 40 to 50 mph are forecast for the area.
Winds delayed arriving and departing flights at the Oakland and San Francisco International airports, officials said.
The weather service warned that dry trees could topple and bring down power lines. "Driving may be difficult, especially for high-profile vehicles," it said.
Pacific Gas and Electric Co. said several there were several power outages in the Bay Area and that power was restored to hundreds of affected customers a few hours later.
Central California could also see winds gusting up to 55 mph and higher peaks in the Sierra Nevada could see up to two feet of snow, the weather service said.
In Southern California, chains were required Saturday on several roads leading to the Bear Mountain and Snow Summit resorts after several inches of snow fell on the San Bernardino Mountains.
A storm Friday dropped 6 inches at higher elevations and brought rain, hail and thunderstorms elsewhere.
The National Weather Service said daytime temperatures in the mountains will stay in the 30s through the weekend and that more snow is expected before Monday.
The Southern California coast remains under a high surf advisory through Sunday, with unpredictable waves topping 10 feet.
Forecasters have said a strong El Nino weather system could drench California and other parts of the West in the coming months. However, Johnny Burg, a meteorologist with the National Weather Service in Seattle, said he didn't believe the latest Northwest storms were related to El Nino, a warming in the Pacific Ocean that can alter weather worldwide.