Authorities reopened Interstate 5 through the Grapevine in California in both directions early Thursday afternoon, ending a closure forced by heavy snow as a second powerful winter storm moved into Southern California on Thanksgiving Day.
California Highway Patrol officers began escorting traffic along the southbound lanes around 1:30 p.m. and reopened the freeway to northbound traffic at 2:55 p.m. Traffic is free flowing, though one lane in each direction remains closed, the CHP said.
Showers and possible thunderstorms were on tap for the Southern California, with rain and snow continuing in Northern California.
The National Weather Service issued flood warnings and advisories for parts of Southern California through Thursday afternoon. Intense downpours of up to half an inch an hour threatened to cause road flooding and mudflows in recent wildfire burn areas, including the hillsides where the Getty fire burned a month ago in Brentwood on the west side of Los Angeles.
Snow fell in Lancaster and other parts of the Antelope Valley and mountain communities, and helped firefighters battling the Cave fire in Santa Barbara County that threatened homes earlier in the week.
The holiday's chilly and gray conditions may seem magnified because they are such a sudden departure from earlier in the month, said climatologist Bill Patzert.
"It was weather whiplash - an abrupt change from hot and dry to unusually frigid. Like 0 to 60 in a Tesla," Patzert quipped.
Interstate 5 through the Tejon Pass was closed around 4 a.m., with the California Department of Transportation urging motorists to use Highway 101 instead. Because the 101 is at a lower elevation, it generally doesn't get enough snow to force a closure.
"We're still plowing and working," said said Eric Menjivar, a spokesman for Caltrans. "It's all hands on deck right now. We're just trying to assist the CHP with whatever they need and also plow the road at the same time so that hopefully we can get it open for everyone to get home in time for Thanksgiving dinner."
Up to 6 inches of snow was forecast for the pass. Snow levels were expected to plunge below 2,000 feet.
Drivers were also urged to use caution when traveling on the 14 Freeway through the Antelope Valley, where snow was still falling about 10 a.m. About 3 inches had accumulated on the valley floor and 4 to 8 inches in the foothills, according to the National Weather Service.
"We're seeing very treacherous driving conditions across the higher elevations, so people need to be aware of that," said Joe Sirard, a meteorologist with the weather service in Oxnard.
The eastbound lanes of Highway 58 were closed for several hours at Towerline Road after multiple collisions were reported near Tehachapi and plows were unable to clear the heavy snow, Caltrans said.
In Orange County, a flash flood warning expired 11:30 a.m. A flood advisory remains in effect, and there were a few reports of minor street flooding.
By 9:30 a.m., slightly more than an inch of rain had fallen in the Huntington Beach area, and between half an inch and seven-tenths of an inch had fallen in San Clemente, the National Weather Service said.
Rainfall totals for the Los Angeles Basin ranged from half an inch to 1 1/4 inches for the 12 hours ending at 9:30 a.m., the weather service said, with 1.18 inches falling in the Montebello area and 1.10 inches around the Sepulveda Dam in the San Fernando Valley.
The rains were being eyed as the cause of a sinkhole that forced the closure of a two-mile section of Turnbull Canyon Road in Whittier.
The hole, about 4 feet wide by 15 feet deep, was reported about 10:30 a.m., said Officer Hugo Figueroa, spokesman for the Whittier Police Department. It was believed to have been caused by a hole in the drainage infrastructure underneath, he said.
"The weather's not making it any better, of course," he said. The road was expected to be closed between Beverly Hills and Skyline drives until at least Monday.
Los Angeles opened several emergency shelters ahead of the storm, making 471 beds available through Friday. More than 1,200 are expected to open over the next month during the city's annual winter roll-out.
In Santa Barbara County, Fire Department spokesman Mike Eliason said he saw the California Highway Patrol managing about half a dozen multicar crashes on the highway around western Goleta and Winchester Canyon as he headed into the mountains to check on the Cave fire.
As he surveyed the smoldering landscape from the top of a ridge, snow began to fall, Eliason said. He was the only one around to see it.
"This is just really unique. We've never had fire with active snowfall near the point of origin. It's very unusual," Eliason said. "It was a very thankful moment. Thankful that no one got injured, no one lost their home. That the snow came over heavy rain. And I'm just thankful that everybody got home safe."
Firefighters were among those returning home, Eliason said.
The Cave fire's official burn area decreased thanks to more accurate mapping from experts, Eliason said, and its containment was expected to climb above 40% by Thursday night as a result of weather conditions.
There are several 800-acre- chunks of unburned land within the fire's perimeter, Eliason added, but all of the blaze's heat is in the middle of its footprint and not on the edges. That suggests the fire won't grow, he said.
Although the snow was a benefit to firefighters, it caused problems for Southern California Edison.
At least 9,000 customers were without power at some point Thursday morning, some of that related to snow damaging the utility's equipment, company officials said.
Among those were about 4,000 customers in Crestline in San Bernardino County, said Edison spokesman Robert Villegas. The rest were spread throughout the utility's 50,000-square-mile territory.
Edison increased staffing and placed workers throughout its service area early to limit chances that repair crews would be cut off from customers because of mud or debris flows, Villegas said.
"We fully anticipate multiple days of stormy weather, so we have our crews working," he said. "It's always a tough thing on holidays for those who aren't going to be home, but it's a part of their job."
Thursday's storm came a day after some areas reported record rainfall, including Santa Barbara Airport, Santa Maria and Lancaster, which had 0.43 inches on Wednesday.
A new winter storm is expected to arrive in Northern and Central California on Saturday, persist through the busy Sunday travel day and continue through Tuesday. It could hit Southern California by next Wednesday and Thursday.
But unlike the Thanksgiving week storms that have resulted from a cold front from the Gulf of Alaska, next week's storm is expected to be fueled by an atmospheric river of subtropical moisture from the west - long plumes of water vapor that can pour over from the Pacific Ocean through California. As a result, there should be heavy precipitation, but it's still too early to pinpoint exactly where rain and snow will be funneled.
"It's kind of like a fire hose, which is hard to control," said Carolina Walbrun, meteorologist with the National Weather Service's Monterey office. "Right now, we're confident that there's going to be rain, and a lot of it, on Saturday afternoon through Sunday. Where the heaviest precipitation is going to be is still uncertain."
Depending on what areas are affected by the atmospheric river, there could be concerns about mudslides for recently burned areas, such as the Kincade fire area of northern Sonoma County, which burned through very steep terrain.
"If that fire hose aims toward that burn scar," Walbrun said, "we're going to have some issues."
Rich Thompson, meteorologist with the weather service's Oxnard office, reiterated that, in Southern California, the atmospheric river could bring a good soaking to the L.A. area by Wednesday or Thursday.
Satellites show even more rain could be lined up behind that.
"I think as far as the fire season, we can say R-I-P," Patzert, the meteorologist, said. "It could always surprise me and get dry in December ... but there are quite a few storms lined up."
Although there are inherent risks with rain immediately following fire, in Patzert's view, it's all gravy for California.
"The state economy thrives or starves depending on the winter snowpack and the rainfall," he said. "For California, this is definitely liquid gold."
This week's weather has caused problems from San Diego to Oregon.
Motorists were stuck overnight on Interstate 5 between Redding and the Oregon border before the roadway was closed. They caught the brunt of the cold statewide storm system, which unleashed heavy rain, blustery winds and low-elevation mountain snow.
The cold front arrived in portions of Northern California on Tuesday, causing headaches for motorists. In San Francisco, which has been essentially dry for eight months, the storm brought about an inch of rain and pea-sized hail. Flooding bedeviled freeways throughout the Bay Area.
Powerful winds rocked northwestern California, with Crescent City in Del Norte County seeing gusts of 60 to 70 mph Tuesday, said Brad Charboneau, a meteorologist with the National Weather Service in Eureka.
A weather phenomenon known as a "bomb cyclone" - a low-pressure system that quickly strengthens - formed off the West Coast, bringing what is believed to be the lowest pressure ever recorded in California to Crescent City on Tuesday, Charboneau said. That low pressure drove the strong winds, he said.
(Times staff writers Hailey Branson Potts, Anh Do, Paige St. John and Hannah Fry contributed to this report.)
Visit the Los Angeles Times at www.latimes.com