San Mateo County (Map, News) - Power outages, flooded streets and falling trees disrupted life on the Peninsula when a storm hit Friday, leaving 123,000 homes in the dark. The county’s blackouts accounted for almost half of all outages in the Bay Area, with most concentrated in Half Moon Bay, Pacifica and Millbrae.

Pacific Gas & Electric was working to fix the power, but warned residents to brace for outages that may last through the weekend.

In response to the storm, San Mateo County opened up its emergency operations center to coordinate efforts with PG&E, Caltrans, the California Highway Patrol and local fire, police and public works agencies that spent the day responding to hundreds of calls. The Bay Area chapter of the American Red Cross was working with the Half Moon Bay Fire Department to assist residents without power.

Hours of rain caused major flooding and traffic delays on U.S. Highway 101 onramps in Millbrae and Burlingame, on northbound 101 near South Airport Boulevard and in northern San Mateo. The Department of Motor Vehicles office in San Mateo had to be closed because it lost power and started to get flooded, said San Mateo Fire Department Chief Dan Belville. San Mateo’s police department had to use its emergency power generator when power went out in the morning.

But the county’s biggest problems were caused by winds, said Lt. Randy Randleman, director of emergency services for San Mateo County.

“All of our damage was wind-caused — trees down and power lines after that,” he said.

Several large trees fell down throughout the county, blocking roadways, ripping power lines and damaging houses. In San Mateo, a tree took down a block’s worth of power lines at Ninth and South Delaware streets, according to the San Mateo Fire Department. Caltrans reported that a fallen tree temporarily closed state Route 92 near Route 35. The Pacifica Police Department cleared several large trees that blocked off main throughways in central Pacifica.

High winds also damaged some mobile homes in Half Moon Bay and brought down roof tiles from the Hampton Inn near Daly City City Hall, closing the nearby area, police said.

The storm brought San Francisco Airport to a near halt, causing up to four-hour delays and more than 80 cancellations of every airline, said SFO spokesman Mike McCarron.

Even access to the airport was hindered by the storm after winds felled trees, blocking BART tracks. BART ran buses from its 24th Street-Mission station for passengers headed to SFO, according to a BART

spokesman.

Downed trees on the tracks caused passengers to evacuate two BART trains and close service between the 24th Street-Mission station and Daly City station and stop trains traveling to SFO from north of Daly City, BART spokesman Jim Allison said.

The storm doused the region with several inches of rain, according to a National Weather Service

forecaster.

“This is the monster storm, the second of three,” forecaster Steve Anderson said.

svasilyuk@examiner.com

Wire services contributed to this report.