The second in a series of storms slammed Northern California on Friday as heavy rain and strong winds knocked out power, tied up traffic and caused flooding along some stretches.
The weather also may be behind the death of a Pacific Gas & Electric worker in West Sacramento who was killed after his truck crashed into a traffic signal pole during the stormy weather.
Flights were delayed at the San Francisco airport, and in the city's affluent Pacific Heights neighborhood, traffic was blocked for hours after a large tree crashed down, smashing a car and obstructing a busy street.
A flash flood watch will remain in effect for most of the San Francisco Bay Area extending to the Santa Cruz Mountains throughout the weekend. A constant barrage of downpours could lead to standing water and overflowing drains, said Diana Henderson, a forecaster with the National Weather Service in Monterey.
The North Bay was seemingly hit the hardest as parts of Sonoma County received more than 7 inches of rain and areas in Napa County received nearly 6 inches, Henderson said.
"It's not a superstorm by any measure, but this is pretty significant," Henderson said. "We should see periods of moderate to heavy rains."
With rain expected all weekend long, Tony Negro, a contractor from Penngrove, Calif., in Sonoma County, said he is worried about water flooding his workshop.
"I'm on my way to get some sand bags," he said.
Thousands of people were without power in that area after an outage that also affected the San Francisco-Oakland Bay Bridge. The suspension span of the bridge was briefly in the dark as traffic was backed up longer than usual because of rain and strong wind gusts.
Also, a mudslide shut down a stretch of Highway 84 east of Fremont, the California Highway Patrol reported. There was no estimate on when it would reopen.
In Sacramento, Interstate 5 south of downtown was blocked in both directions before 9 a.m. Friday after an empty big-rig jackknifed in the southbound lanes and struck the median divider, the CHP said.
"I would definitely say it's weather-related. The reports came in that he hit a water puddle and hydroplaned and couldn't correct," CHP Officer Mike Bradley said. "A lot of high-profile vehicles, especially the lighter ones, are getting windblown and having some problems maintaining their lane."
No one was injured in the crash on I-5, California's main north-south highway. But a second vehicle also was damaged and had to be towed, while workers contained and cleaned up diesel fuel spilled from the tractor-trailer.
In West Sacramento, police say wet conditions may have been a factor when a PG&E worker died after he lost control of his vehicle and slammed into a traffic pole shortly before 2 a.m. Friday.
PG&E workers at the scene tell KCRA-TV that the driver had been working overtime and was returning from Clarksburg in southern Sacramento County.
Henderson said rain in the region is expected to taper a bit Saturday, but return later that night into Sunday. The storms could also create the possibility of rock and mud slides in areas already saturated and have been affected by wild fires earlier this summer.
In Los Angeles, conditions were wet and gloomy as downtown skyscrapers disappeared in low-hanging clouds.
Elsewhere in the West, authorities in Northern Nevada have cancelled Christmas parades and tree lightings in Sparks and Truckee, which are located just across the border from California.
In nearby Reno, city spokeswoman Michele Anderson said public servants would be working overtime through the weekend to control what's expected to be the worst flooding there since 2005.
Also, a storm rushed through southern Oregon this week, lingering inland over the Rogue Valley and dropping record rainfall.
It largely spared coastal Curry County on Thursday and its southernmost city, Brookings, which are recovering from a storm earlier this month.
"We are still vigilant for landslides and road closures and trees down, but so far — knock on wood — we are still good to go," Curry County Sheriff John Bishop said Friday.
Forecasters said the region should expect more storm systems over the next few days.
Associated Press writers Haven Daley in San Francisco, Don Thompson in Sacramento, Calif., John Antczak in Los Angeles, Hannah Dreier in Las Vegas, Jeff Barnard in Grants Pass, Ore., and Tim Fought in Medford, Ore., also contributed to this report.