SAN FRANCISCO (AP) — Days of rain and snow across California have snarled rush-hour commutes and triggered deadly wrecks on slick roads even before the most intense storm hits Wednesday, with wildfire-ravished communities bracing for dangerous mudslides and mountain residents facing a "potentially life-threatening" blizzard.
A series of storms dropped rain up and down the state and snow in mountain regions this week, but the latest storm could be the strongest that Northern California has seen so far this year.
"A powerful Pacific storm will hammer the West Coast into Friday with strong winds, heavy rain and heavy mountain snow," the National Weather Service said. "Heavy rain will bring a threat of flash flooding along recent burn scars while blizzard conditions are expected" in the Sierra Nevada.
Authorities in areas recently scarred by wildfires fear small rivers and creeks flooding their banks and causing massive mudslides, further damaging communities struggling to recover from a historically bad fire season.
The blazes stripped hillsides of trees and other vegetation that stabilize soil and prevent mudslides, putting at risk thousands of people living in foothill and canyon areas devastated by wildfires. That includes the Northern California region where a November fire killed 86 people and destroyed nearly 15,000 homes.
"If flooding occurs, this can quickly become a dangerous and life-threatening situation," the Butte County Sheriff's Office said.
Authorities told residents of Pulga to prepare to flee their canyon community that neighbors the town of Paradise, which was virtually incinerated two months ago by the Camp Fire.
A blizzard warning covered the Sierra Nevada and Lake Tahoe regions, where as much as 5 feet of snow was expected.
The San Francisco Bay Area was forecast to see heavy rain, and residents were warned to watch for flash floods through the end of the week.
The Sacramento area faced flood and high wind watches, with gusts that could lead to power outages, downed trees and tough driving conditions.
Even before the worst of this week's storms hit, conditions deteriorated on California roadways.
Three people, including an infant, were killed Tuesday night when their car spun out on a freeway in Placerville, about 130 miles east of San Francisco. The California Highway Patrol blamed the wreck on high speed and rain-slickened roads.
Fog on a mountain highway in Southern California triggered a 19-vehicle crash Wednesday. Thirty-five people were evaluated for injuries after the pileup on Interstate 15 in Cajon Pass, but most declined to be taken to hospitals, the San Bernardino County Fire Department said.
A mudslide on a major Northern California freeway just north of the Golden Gate Bridge snarled the morning commute. The slide closed southbound Highway 101 across the bridge for about an hour, shutting off the only direct access to San Francisco for drivers north of the city.
In the mountainous community of Truckee where it snowed Tuesday, residents were preparing for another storm by clearing driveways and buying wood and food in case they have to stay inside.
"It took my husband an hour to get to Safeway last week because there were so many people and no one could get home," Whitby Bierwolf told the Sacramento television station KCRA. "You just need to have an alternate plan and have enough stuff in your car because accidents happen."
In the south, some evacuation orders were in place in the Malibu area west of Los Angeles and parts of neighboring Ventura County. Both were affected by a November fire that destroyed more than 1,500 homes and killed four people.
Paul Manion was busy filling sandbags in the community of Bell Canyon.
"It's something we have to do. I mean, if the water comes, it comes," Manion told KABC-TV. "Everything around our house burned. All the houses around our house burned. But it's the hillsides that we're worried about."
Others refused to leave after authorities went door to door at the high-risk Paradise Cove mobile home park in Malibu.
Beaver Valenzuela said he's survived fiercer storms and wouldn't leave until he was convinced the danger was more immediate.
"I'm not going anywhere," he told the Los Angeles news station.