Surfer and Huntington Beach lifeguard Jachin Hamborg watches the dramatic sky and waves after surfing following his lifeguarding shift at dusk at the Huntington Beach pier.(Allen J. Schaben / Los Angeles Times)
A man is silhouetted against a dramatic sky at sunset while walking on the Huntington Beach pier.(Allen J. Schaben / Los Angeles Times)
Pedestrians stay dry in the rain on 5th Street in downtown Los Angeles.(Christina House / Christina House)
A pedestrian takes to flight crossing 4th Street in Santa Ana after heavy rain flooded the area.(Allen J. Schaben / Los Angeles Times)
Snowplows clear Highway 18 during a storm on Jan. 12, 2017, in Running Springs.(Gina Ferazzi / Los Angeles Times)
Jessica Pompa and Albert Arroyo make a snowman at Firehouse Park in Running Springs.(Gina Ferazzi / Los Angeles Times)
Michelle Graves keeps an eye on the sky as she waits to cross Spring Street in downtown Los Angeles.(Luis Sinco / Los Angeles Times)
Laurel Canyon Boulevard remained closed in both directions Thursday morning in the Hollywood Hills after part of a home’s concrete foundation tumbled down a hillside after a round of rainfall.(Al Seib / Los Angeles Times)
News crews gather on Laurel Canyon Blvd, which remained closed in both directions Thursday morning in the Hollywood Hills when part of a home’s concrete foundation tumbled down a hillside after a round of rainfall.(Al Seib / Los Angeles Times)
A pedestrian wades through a flooded 4th Street in Santa Ana.(Allen J. Schaben / Los Angeles Times)
Traffic moved slowly on a snowy Highway 18 in the Running Springs area.(Gina Ferazzi / Los Angeles Times)
Members of a film crew shelter under umbrellas as the rain comes down in front of L.A. City Hall.(Luis Sinco / Los Angeles Times)
A pedestrian wades through a flooded 4th Street in Santa Ana carrying her daughter.(Allen J. Schaben / Los Angeles Times)
A man crossing the street gets caught in a heavy burst of rain on 4th Street in Santa Ana.(Allen J. Schaben / Los Angeles Times)
Bruce MacDonnell paddles over a flooded road in Guerneville on Wednesday after the Russian River crested.(Kent Porter / Press Democrat)
A dog swims pass a flooded dinosaur display at Playland Miniature Golf Course in Guerneville on Wednesday.(Kent Porter / Press Democrat)
With Russian River waters rising, Dustin Coupe of Guerneville talks with an operator at a phone booth on River Road. Dozens of Northern California residents have been rescued by boats and firetrucks from flooded homes near Hollister.(Kent Porter / Press Democrat)
A Guernville resident walks down steps toward the foodwater surrounding his home.(Justin Sullivan / Getty Images)
Residents get out of their canoe in front of the Pee Wee Golf and Arcade on Drake Road in Guerneville.(John G. Mabanglo / European Pressphoto Agency)
Residents paddle along River Lands Road in Guerneville.(John G. Mabanglo / European Pressphoto Agency)
The entrance to Stealhead Beach Park in Forestville is closed on Wednesday because of flooding.(John G. Mabanglo / European Pressphoto Agency)
A woman walks through water from a king tide that flooded onto the Embarcadero in San Francisco on Wednesday.(Jeff Chiu / Associated Press)
Caltrans worker Brad Larson is whipped by high winds on Tuesday as he mans a checkpoint closing all northbound traffic at U.S. 395 and State Route 203 near Mammoth Lakes.(Brian van der Brug / Los Angeles Times)
Caltrans worker Mark Reistetter tells a Reno-bound truck driver his options at a checkpoint closing all northbound traffic at U.S. 395 and State Route 203 near Mammoth Lakes.(Brian van der Brug / Los Angeles Times)
More than 100 trucks line Main Street in Lone Pine on Tuesday, stranded as U.S. 395 closed to high-profile vehicles in both directions because of high winds.(Brian van der Brug / Los Angeles Times)
A Mammoth Mountain employee directing traffic is dwarfed by a snow removal vehicle on Minaret Road leading to the Mammoth Mountain ski area in Mammoth Lakes.(Brian van der Brug / Los Angeles Times)
A tow truck driver pulls a pickup truck out of a snowbank in the median of U.S. 395 near Mammoth Lakes.(Brian van der Brug / Los Angeles Times)
Clouds drift over the Owens Valley in a view from above Round Valley near Bishop.(Brian van der Brug / Los Angeles Times)
Emma Soriano jumps in a puddle on the Manhattan Beach Pier after posing for pictures for her dad.(Jay L. Clendenin / Los Angeles Times)
With the Manhattan Beach Pier in the distance, surfers scan the waves of Hermosa Beach.(Jay L. Clendenin / Los Angeles Times)
Morgan Harris of Hermosa Beach rides home along The Strand after a couple of hours of surfing south of Hermosa Beach.(Jay L. Clendenin / Los Angeles Times)
A biker at Hermosa Beach, where people were dealing with a lingering rainstorm.(Jay L. Clendenin / Los Angeles Times)
A break in a series of storms moving across California highlights the snow-covered White Mountains looming over U.S. Highway 395 in Crowley Lake.(Brian van der Brug / Los Angeles Times)
Traffic moves slowly at the Donner Pass Road exit on snowy Interstate 80 in Soda Springs.(Gary Coronado / Los Angeles Times)
The Green Church, a beloved landmark along U.S. 395, is partly obscured by snow during a break in a series of storms in the Eastern Sierra Nevada near Mammoth Lakes.(Brian van der Brug / Los Angeles Times)
Snow falls along Interstate 80 at Exit 184 in Truckee.(Gary Coronado / Los Angeles Times)
A break in a series of storms in the Eastern Sierra Nevada highlights the snow-covered White Mountains near Convict Lake.(Brian van der Brug / Los Angeles Times)
A plow removes freshly fallen snow along Donner Pass Road in Soda Springs, Calif.(Gary Coronado / Los Angeles Times)
On a snowy day, a sign makes it clear that chains are required on this stretch of Interstate 80 in Truckee.
(Gary Coronado / Los Angeles Times)
Jack Ryan and his family came out to see firsthand water cresting the south bank of the American River, flooding American River Parkway in Sacramento’s Discovery Park.(Gary Coronado / Los Angeles Times)
Folsom Lake continues to rise as the Folsom reservoir releases water into the American River.(Gary Coronado / Los Angeles Times)
Traffic is backed up while CalTrans removes falling rocks and mud which closed one westbound lane along Interstate 80 east of Truckee, near Floriston, Calif.(Gary Coronado / Los Angeles Times)
Wendy Payne of CalTrans clears debris along Highway 89 near Truckee.(Gary Coronado / Los Angeles Times)
Park Ranger Cullen Tucker walks across a bridge during a rain storm on the Merced River in Yosemite National Park.(Gary Kazanjian / Associated Press)
Mammoth Mountain ski patrolman Cliff Klock, left, and Forest Service member Jeff Karl fire a 105-millimeter howitzer on Sunday to mitigate avalanche paths at the top of the ski area in Mammoth Lakes, Calif.(Brian van der Brug / Los Angeles Times)
Mammoth Mountain ski patrolman Cliff Klock prepares to load a 105-millimeter shell into the breach of a 1943 howitzer.(Brian van der Brug / Los Angeles Times)
Mammoth Mountain ski patrol clear avalanche chutes on Sunday morning after a night of snow.(Brian van der Brug)
A CHP officer proclaims “aw man!” as he is photographed after becoming stuck in heavy snow in the median of US 395 near Crowley Lake as snow falls on the Eastern Sierra Nevada.(Brian van der Brug / Los Angeles Times)
Monique Long hauls sandbags from her SUV to make a barrier to divert the rain and melting snow from flooding her garage, while her friend Jenna Shropshire, right, helps shovel snow, in Truckee, Calif.(Gary Coronado / Los Angeles Times)
Mitch Brown operates a skid steer removing snow so water can flow freely preventing flooding in Soda Springs, Calif.(Gary Coronado / Los Angeles Times)
Skiers coming off the mountain endured rainy conditions all day at the Sugar Bowl Ski Resort, in Norden, Calif.(Gary Coronado / Los Angeles Times)
The train passes under an avalanche tunnel near the Sugar Bowl Ski Resort, in Norden, Calif., on Jan. 7, 2017.(Gary Coronado / Los Angeles Times)
Caltrans snowplows clear heavy snow from the northbound lanes oh highway 395 as snow falls on the Eastern Sierra near Sherwin Summit, Calif.(Brian van der Brug / Los Angeles Times)
Actor Max Baer Jr., left, talks with emergency responders after flipping over his SUV in white-out conditions while traveling northbound on U.S. 395 near Crowley Lake as heavy snow falls on the Eastern Sierra Nevada, Calif. The star of The Beverly Hillbillies said his was not injured.(Brian van der Brug / Los Angeles Times)
A snowcat moves snow in near whiteout conditions on the slopes at Mammoth Mountain.(Brian van der Brug / Los Angeles Times)
A CHP officer maintains a checkpoint to ensure vehicles are compliant with R2 chain restrictions on the northbound 395 just north of Bishop as snow falls on the Eastern Sierra Nevada.(Brian van der Brug / Los Angeles Times)
Caltrans crews have a road-flooded sign in case of heavy rain and snow near the Eastern Sierra Nevada town of June Lake, Calif.(Brian van der Brug / Los Angeles Times)
Caltrans avalanche crew members Sky Greytak, right, and Pat Brannen, left, prepare to set off explosive charges remotely from a laptop during avalanche control operations near the Eastern Sierra Nevada town.(Brian van der Brug / Los Angeles Times)
Caltrans snowplow operator Mike Morgan prepares to turn his plow around after making loops on the 395 between Bishop and Tom’s Place, a route he drives 12 hours a day clearing heavy snow in the Eastern Sierra.(Brian van der Brug / Los Angeles Times)
Mammoth Mountain employees clear paths as snow falls lightly Saturday morning.(Brian van der Brug / Los Angeles Times)
A car spun out and off the road just outside Bishop in sloppy road conditions as the snowfall level fell below 5000.(Brian van der Brug / Los Angeles Times)
California Highway Patrol has established a chain checkpoint near Bishop.(Brian van der Brug / Los Angeles Times)
Chris Guyot, 13, Kayleigh, 10, and their mom, Tricia, and the rest of the family, Evan Guyot, and Tyler, 19, (not pictured) of Orange, Calif., pack up their belongings after being told to evacuate the Yosemite Valley Lodge, in Yosemite National Park. A massive storm bearing down on Central California could overflow rivers, trigger rockslides and topple trees, prompting rangers at Yosemite National Park to close roads to the valley floor.(Michael Macor / San Francisco Chronicle)
Snow covers vehicles in a parking lot in Mammoth Lakes.(Brian van der Brug / Los Angeles Times)
Jorge Gaydam digs out his truck in a parking lot.(Brian van der Brug / Los Angeles Times)
Snow blankets the Sierra Nevada crest north of Bishop along U.S. Highway 395 in Round Valley.(Brian van der Brug / Los Angeles Times)
A plow removes snow from state Highway 203 in Mammoth Lakes.(Brian van der Brug / Los Angeles Times)
The first band of what forecasters predict will be the region’s most powerful storm in a decade continued to pummel Northern California on Sunday, causing flooding throughout the region and prompting evacuations in Sonoma County and parts of neighboring Nevada.
Emergency officials voluntarily evacuated 650 homes in the low-lying communities of Monte Rio and Guerneville in Sonoma County as the Russian River continued to rise Sunday evening. The river is expected to peak at noon on Monday and will probably remain at or above flood levels through Tuesday morning, officials said.
Authorities said nearly 400 homes in Reno and other areas of Washoe County, Nev., were voluntarily evacuated Sunday due to widespread flooding that is expected to worsen overnight and into Monday.
Officials expect the Truckee River to crest 1 to 2 feet above flood stage by 10 p.m. on Sunday in Reno and reach its highest level at 6 feet above flood stage by 7 a.m. Monday in neighboring Sparks.
One Reno neighborhood was placed under voluntary evacuation orders because of a storm-related sewage station failure that poses a health hazard.
High-elevation rain and snowmelt from the warm storm was causing smaller upper tributaries to flood as well. Streams in the Lake Tahoe basin were full or spilling out of their banks Sunday evening, forecasters said.
“There’s a significant threat to life and property as we go through the next couple of days with widespread flooding, continued road closures and high water in low-lying areas,” said Mark Faucette, a National Weather Service forecaster based in Reno. “This is beyond localized flooding. This is a significant flood event.”
The Reno area is expected to experience the worst flooding in a decade.
“The last time the river flooded like this in Reno was in 2005,” Faucette said.
Officials warned the public to heed any evacuation orders and to stay out of any flooded roads or areas, especially at night when it might be difficult to see the water or determine how deep it is.
A major mudslide Sunday evening on Donner Summit, just west of Truckee, closed Interstate 80 in the Sierra Nevada in both directions, cutting off the main transportation route between Reno and San Francisco.
California Highway Patrol Officer Peter Mann said the flow of mud and rock extended across the road for about the length of a football field and was 7 feet deep in some places. Downed power lines complicated cleanup efforts and the road was expected to remain closed for hours.
“The mess just keeps getting better,” Mann said.
An “extreme” avalanche warning was issued for parts of the Sierra Nevada because of the heavy snow. In Mammoth Lakes, officials said higher elevations recorded 48 inches of snow in the last two days.
Winds topped 50 mph in some areas. A woman was killed in the East Bay suburb of San Ramon on Saturday when she was struck by a falling tree at a golf course amid heavy winds.
More than 91,000 PG&E customers in Central and Northern California were without electricity as of Sunday afternoon as rain, snow and winds caused flooding and knocked down power lines, said PG&E spokesman Paul Doherty.
Those who lost power were spread across PG&E’s service area, which stretches from Bakersfield in the south to Eureka in the north.
In the San Francisco Bay Area alone, 33,200 customers didn’t have power as of 2:45 p.m., Doherty said.
“Obviously we’ve seen the storm pick up in intensity today,” he said Sunday afternoon.
Doherty said PG&E had prepared for the major storm and had extra crews — a total of 1,400 people — that were ready to respond to outages. The agency set up an emergency operations center in downtown San Francisco, as well as a staging area in the Santa Cruz Mountains to be prepared to respond to outages there.
Doherty said he expected most customers’ power would be restored by late Monday, but that another strong storm was expected on Tuesday and Wednesday.
“We’ll have our emergency operations center as long as necessary,” he said.
Yosemite Valley remained closed to visitors because of heavy rain and flooding. The Merced River at Pohono Bridge was nearing 10 feet (flood stage) and was forecast to reach 11.8 feet Sunday night.
The park will assess conditions early Monday morning, officials said. There is no anticipated date or time for roads into Yosemite Valley and guest services to reopen.
Mammoth Lakes residents girded for flooding as heavy rain fell early Sunday, melting mounds of piled-up snow and sending water and slush into the streets of the eastern Sierra Nevada ski town.
“My garage is flooding with 2 inches of water,” said Nick Criss, 40, as he shoveled sand into bags at the town public works yard.
Criss, a 12-year Mammoth Lakes resident, worries his home and many others will be damaged by the gush of rainwater and melted snow.
“There’s nowhere for the water to go,” he said.
Lifts at Mammoth Mountain resort were not operating Sunday morning because of high winds, thunder and lightning.
Visiting skiers and snowboarders were packing up their cars to head home Sunday morning.
As Mammoth Lakes emptied out, the town rattled with the crash of thunder, lightning and the sound of huge slabs of snow sliding off roofs onto the ground.
Erik Radatz, 45, who runs a pet grooming salon in Mammoth Lakes, rushed to shovel sand into sandbags to protect his home Sunday as the rain came down.
“If the temperature stays warm like this, it’s going to be bad,” Radatz said.
His advice for anyone from Los Angeles thinking of heading up to Mammoth?
“Stay home,” he said. “But if you do come, don’t bring skis — bring water skis.”
Rain fell heavily overnight on Donner Summit, just west of Truckee, with nearly 4 inches by morning. Forecasters expect a total of 6 to 12 inches Sunday.
“It’s turned the snow into cement, " said a tow truck driver for AAA. He had pulled six vehicles out of the slush pack by 10 a.m. Sunday and had other stranded drivers waiting, many of them in four-wheel-drive vehicles.
California Highway Patrol crews have repeatedly had to dig out ice dams blocking drainage culverts in Soda Springs, trapping stragglers from Saturday’s ski rush in the mountains who are now trying to reach Interstate 80.
The North Tahoe Fire District issued an avalanche warning for residents in the Incline Village area, warning them that expected collapse of snow will bring an “air wave” that will rattle windows. No structural damage is expected.
Matt Robinson, a spokesman for Sacramento County, says officials are inspecting the conditions of levees throughout the region.
“These are areas that always flood when we have heavy rain,” Robinson said. “Some of these levees are old, and they may not be able to withstand the pressure.”
The worst flooding could be in Wilton, which is the southern part of Sacramento County. Officials announced a voluntary evacuation on Saturday afternoon, and a handful of people showed up at the evacuation center in Elk Grove Park.
The so-called atmospheric river of airborne moisture known as the Pineapple Express will be felt across much of the state, but especially in the Sierra, bringing with it warm snow-eating rain, forecasters said.
Mammoth Lakes residents worried that the warm rain and slush would dam up behind banks of shoveled snow piled high in empty lots and along roads throughout town, then flow wherever it could find a path, clogging existing drainage systems with debris and ice.
“In this town, we don’t even have rain gutters because they get ripped down by snow,” said Lisa Isaacs, a resident and environmental activist. “So we’re very worried that this storm will flood homes and garages.”
Town officials advised residents to stock up on water, food, first aid supplies, clothing and bedding, tools and emergency supplies, along with special items for medical conditions. The city of 8,000 is perched at an elevation of 7,880 feet.
On a winter war footing, residents lined up throughout the day on Saturday at the town’s utility yard to load up on 40-pound sandbags they hoped would steer waves of slush away from homes, ground-floor condominiums and businesses.
Among them were Greg Newbry, 66, a recently retired Mono County employee, and his wife, Linda Salcido, 67, Mono County’s director of public health.
“I was here in 1982 when this town was wrecked by massive flooding,” Newbry recalled. “Main Street was under 2 feet of water. Businesses closed. The roofs of five mobile homes collapsed under the weight of rain on snow.
“If we get all the rain predicted in the forecasts,” he added, “every slab of concrete at ground level is vulnerable, and we live in a ground-floor condominium.”
As she helped tote 20 sandbags to their vehicle, Salcido said she was concerned about the potential effects of flooding countywide.
“Snow, even lots and lots of it, we can handle,” she said. “But a major flood event would lead to countless challenges.”
We’ve got cars everywhere, upside-down and everything.
Crews and residents in area towns spent Saturday preparing for the deluge. Snowplow operators scraped icy roadways. Excavators and snowblowers cleared and moved huge piles of snow. In the eastern Sierra Nevada, Caltrans workers used explosive devices to clear snow from avalanche-prone areas.
“It’s the rain over the snow that we’re worried about,” said Greg Miller, Caltrans maintenance manager for the region. We’ve had snow since Christmas, but now, with the warmer trend, we’re worried about water.”
From his white SUV, Miller kept a close eye on conditions along U.S. 395. The reports heard over radio traffic told the story.
Cars rolling over and sliding off the road. An irate driver blocking a plow truck. Someone driving the wrong way on the highway.
At one point, a request went out to bump up to stricter tire chain controls as road conditions worsened. Later, a California Highway Patrol vehicle slid into a median and had to be pulled out.
“We’ve got cars everywhere, upside-down and everything,” Miller reported over the phone.
Maintenance crews were kept busy responding to snow-related accidents and icy road conditions.
Steve Coons manned a massive Caltrans wing plow. Its engine strained as it worked in tandem with another truck to clear and sand two northbound lanes of U.S. 395 north of Bishop, a key transportation corridor along the Eastern Sierra Nevada.
From behind the wheel of the rumbling truck, Coons could feel the weight of the heavy, wet snow as it pushed against the plow blade and was shoved to the side of the highway.
“The truck is really chugging,” he said. “It’s going to be a long day.”
Coons monitors closely the consistency of the snow, which wavers between soft, large flakes and icy shards. The more of it that falls as rain and ice, the more he worries it will make the roads slick and cause serious trouble for drivers.
“As soon as it gets cold, all this ices up,” Coons said. “Not good.”
He and other plow operators are on the roads 24 hours a day, working 12-hour shifts. They will have no shortage of snow to clear with the series of storm cells expected to continue dumping moisture over the area for days.
“Our guys have pretty much been on since Christmas, and it’s not letting up,” said Greg Miller, maintenance manager for Caltrans District 9, which includes Inyo, Mono and eastern Kern Counties.
In Truckee, a small resort town north of Lake Tahoe, residents filled sandbags at the local fire station to shore their homes against the water.
Monique Long hefted heavy bags of sand into the back of her family GMC. The waist-high snow around her neighborhood was melting rapidly, and some of it was streaming down a nearby hill, straight into her garage.
“Everything is quickly coming up,” she said.
To the south in Mammoth Lakes, highway patrols responded to snow-related accidents as road conditions worsened.
Isaacs spent Saturday hoping that “the rain they keep talking about will turn out to be snow.”
“But it’ll probably be like having a giant fire hose turned on us and we’ll be swamped,” she said with a nervous laugh. “I just hope that my little $150 water pump can keep up with it.”
Mammoth Mountain Chief Executive Rusty Gregory had few answers.
“The main topic of conversation over cocktails on Sunday night,” he mused, “will be about what actually happened that day.”
Los Angeles Times staff writer Rosanna Xia contributed to this report.
MORE ON THE STORMS:
8:15 p.m.: This article was updated with new details about evacuations in Sonoma County and neighboring Nevada.
7:50 p.m.: This article was updated with new information regarding weather and flooding conditions.
6:11 p.m.: This article was updated with new information about flooding throughout the region and voluntary evacuations in neighboring Nevada.
5:30 p.m.: This article was updated with new information about Yosemite Valley and on flooding conditions around Truckee.
4 p.m.: This article was updated with new information about power outages in the Bay Area.
3 p.m.: This article was updated to include new information about possible flooding conditions in the Sacramento area.
12:20 p.m.: This article was updated with new information about road closures.
11:10 a.m. This article was updated with new details about weather conditions in the Mammoth Lakes area.
10 a.m.: This article was updated with flooding information in North Bay.
8 a.m.: This article was updated with new information about the overnight storm.
This article was originally published at 3 a.m.