One of the strongest West Coast storms in years hit northern and central California on Thursday, drenching the region with as much as 13 centimeters (5 inches) of rain, accompanied by wind gusts of 230 kilometers (140 miles) an hour.
The storm closed San Francisco Bay-area schools, flooded highways and knocked out power to nearly 227,000 customers. A downtown subway station serving San Francisco's financial district was closed through the morning commuter rush because of a power outage, and the city's electrified bus system was halted in many areas, transit officials said.
Nearly 240 departing and incoming commercial flights had been canceled at San Francisco International Airport by late morning, and delays for other flights averaged two hours, airport duty manager Bob Ritiski said.
Northeast of San Francisco, winds howled through Sacramento, the state capital, rattling buildings and whipping through trees before dawn, followed by heavy downpours as the morning commute was getting started.
The National Weather Service issued flash-flood, heavy-surf and high-wind advisories for the region, warning that torrential rains could lead to mudslides in foothill areas scarred by wildfires earlier in this year.
As much as a meter (3 feet) of snow was predicted this week for higher elevations of the Sierra Nevada mountain range. But meteorologists said many months of rainfall would be needed to pull the state out of its record, multiyear drought.
The storm was expected to spread by Thursday night into Southern California, in what would be area's second major storm in a week. A third storm system has been forecast for this weekend.
Municipalities handed out sandbags to help residents ward off flooding and reminded them to stock up on emergency supplies.
Supermarkets were emptied of bottled water Wednesday night. At a SaveMart supermarket in Sacramento, shoppers combed the aisles for prepared foods that could be served without cooking in case of a long blackout.
Some information for this report came from Reuters.