An atmospheric river dumping rain across Northern California and several feet of snow in the Sierras was making its way across the state Friday, bringing flooding and threatening mudslides along with it.

The storm, the first big one of the season, moved over California as a bomb cyclone, a description of how it rapidly intensified before making its way onshore.

On Thursday, rain poured across the northern edge of the state, slowly moving south. It rained 3.66 inches in Ukiah on Thursday, breaking the record for the city set in 1977 by a half-inch. Santa Rosa Airport saw 4.93 inches of rain on Thursday, shattering the daily record set in 2001 of 0.93 inches.

More rain is due Friday.

“Prolonged rainfall will result in an increased risk of flooding, an increased risk of landslides, and downed trees and power lines across the North Bay,” the National Weather Service’s Bay Area office wrote in a Friday morning forecast.

After its initial peak, the system is expected to linger into the weekend, with a second wave of rainfall extending farther south across most of the San Francisco Bay Area, down into the Central Coast and possibly reaching parts of Southern California.

On Saturday, Los Angeles and Ventura counties could see anywhere from a tenth to a third of an inch of rain. San Luis Obispo and Santa Barbara counties could see up to an inch in some areas.

A second round of rain expected to begin Sunday could be “a little stronger than the first but still likely in the ‘beneficial rain’ category,” the National Weather Service said in its latest L.A. forecast.

Chances are low of flooding or any other significant issues in Southern California, forecasters said, though roads could be slick and snarl traffic.

Staff writer Grace Toohey contributed to this report.

A major storm moving through Northern California on Thursday dropped heavy snow and record rain, flooding some areas, after killing two people and knocking out power to hundreds of thousands in the Pacific Northwest.

Forecasters warned that the risk of flash flooding and rockslides would continue, and scores of flights were canceled at San Francisco’s airport.

In Washington, nearly 223,000 people — mostly in the Seattle area — remained without power as crews worked to clear streets of electrical lines, fallen branches and debris. Utility officials said the outages, which began Tuesday, could last into Saturday.

Meanwhile on the East Coast, where rare wildfires have raged, New York and New Jersey welcomed much-needed rain that could ease the fire danger for the rest of the year.

The National Weather Service extended a flood watch into Saturday for areas north of San Francisco as the region was inundated by this season’s strongest atmospheric river — a long plume of moisture that forms over an ocean and flows through the sky over land.

The system roared ashore Tuesday as a ” bomb cyclone,” which occurs when a cyclone intensifies rapidly. It unleashed fierce winds that toppled trees onto roads, vehicles and homes, killing at least two people in the Washington cities of Lynnwood and Bellevue.

Communities in Washington opened warming centers offering free internet and device charging. Some medical clinics closed because of power outages.

“I’ve been here since the mid-’80s. I haven’t seen anything like this,” said Trish Bloor, who serves on the city of Issaquah’s Human Resources Commission, as she surveyed damaged homes.

Up to 41 centimeters of rain was forecast in southwestern Oregon and California’s northern counties through Friday.

Santa Rosa saw 16.5 centimeters of rain in the last 24 hours, marking the wettest day on record since 1998, according to Joe Wegman, a meteorologist with the National Weather Service.

The Sonoma County Airport, in the wine country north of San Francisco, got more than 28 centimeters within the last 48 hours. The Ukiah Municipal Airport recorded about 7.6 centimeters Wednesday, and the unincorporated town of Venado had about 32.3 centimeters in 48 hours.

In nearby Forestville, one person was hurt when a tree fell on a house. Small landslides were reported across the North Bay, including one on State Route 281 on Wednesday that caused a car crash, according to Marc Chenard, a weather service meteorologist.

Daniela Alvarado said calls to her and her father’s Sonoma County-based tree business have nearly tripled in the last few days, with people reaching out about trimming or removing trees.

“We feel sad, scared, but also ready for action,” Alvarado said.

Rain slowed somewhat, but “persistent heavy rain will enter the picture again by Friday morning,” the weather service’s San Francisco office said on the social platform X. “We are not done!”

Dangerous flash flooding, rockslides and debris flows were possible, especially where hillsides were loosened by recent wildfires, officials warned. Scott Rowe, a hydrologist with the weather service in Sacramento, said that so far the ground has been able to absorb the rain in Butte and Tehama counties, where the Park Fire burned this summer.

“It’s not necessarily how much rain falls; it’s how fast the rain falls,” Rowe said.

Santa Rosa Division Chief Fire Marshal Paul Lowenthal said 100 vehicles were stuck for hours in the parking lot of a hotel and medical center after being swamped by thigh-high waters from a flooded creek.

A winter storm watch was in place for the northern Sierra Nevada above 1,070 meters, with 38 centimeters of snow possible over two days. Wind gusts could top 121 kph in mountain areas, forecasters said.

Sugar Bowl Resort, north of Lake Tahoe near Donner Summit, picked up 30 centimeters of snow overnight, marketing manager Maggie Eshbaugh said Thursday. She said the resort will welcome skiers and boarders on Friday, the earliest opening date in 20 years, “and then we’re going to get another whopping of another foot or so on Saturday, so this is fantastic.”

Another popular resort, Palisades Tahoe, said it is also opening Friday, five days ahead of schedule.

The storm already dumped more than 30 centimeters of snow along the Cascades in Oregon by Wednesday night, according to the weather service.

More than a dozen schools closed in the Seattle area Wednesday, and some opted to extend the closures through Thursday.

Covington Medical Center southeast of Seattle postponed elective surgeries and diverted ambulances after losing power and having to rely on generators Tuesday night into Wednesday, according to Scott Thompson, spokesperson for MultiCare Health System. Nearby, MultiCare clinics closed Wednesday and Thursday after losing power.

In Enumclaw, also southeast of Seattle, residents were cleaning up after their town clocked the highest winds in the state Tuesday night: 119 kph.

Ben Gibbard, lead singer of the indie rock bands Death Cab for Cutie and Postal Service, drove from his Seattle neighborhood Thursday morning to the woods of Tiger Mountain for his regular weekday run, but trees were blocking the trail.

“We didn’t get hit that hard in the city,” he said. “I just didn’t assume it would be this kind of situation out here. Obviously you feel the most for people who had their homes partially destroyed by this.”

Washington Gov. Jay Inslee thanked utility crews for toiling around the clock. It could take weeks to assess the scope of the damage and put a dollar figure on it, he said in a statement, and after that “we’ll know whether we will be able to seek federal assistance.”

In California, there were reports of nearly 13,000 power outages.

Authorities limited vehicle traffic on part of northbound Interstate 5 between Redding and Yreka due to snow, according to California’s Department of Transportation. Officials also shut down a 3.2-kilometer stretch of the scenic Avenue of the Giants, named for its towering coast redwoods, due to flooding.

About 550 flights were delayed and dozens were canceled Thursday at San Francisco International Airport, according to tracking service FlightAware.

Parched areas of the Northeast got a much-needed shot of precipitation, providing a bit of respite in a region plagued by wildfires and dwindling water supplies. More than 5 centimeters was expected by Saturday morning north of New York City, with snow mixed in at higher elevations.

Weather service meteorologist Brian Ciemnecki in New York City, which this week saw its first drought warning in 22 years, said “any rainfall is going to be significant” but the storm will not be enough to end the drought.

If one oarfish landing on a beach is a sign of a disaster to come, how bad will it be if three wash up in quick succession?

A silvery 10-foot-long creature, the oarfish has fueled fisherman’s tales of sea serpents — and in some cultures has been a portent of natural disasters.

It’s rare to see an oarfish up close in California; only 22 have washed ashore since 1901, according to UC San Diego’s Scripps Institution of Oceanography. But in the last three months, three of them have surfaced on Southern California beaches.

The latest was on Nov. 6, when an oarfish was discovered at Grandview Beach by Alison Laferriere, a doctoral candidate at Scripps Institution of Oceanography. The other two beached in La Jolla and Huntington Beach.

The last time a series of oarfish came ashore in California and other parts of the world was over several months in 2013 and 2014. Misty Paig-Tran, associate professor of biological science at Cal State Fullerton, studied four of them.

Every time an oarfish makes an appearance on the sand, it’s a spectacle for scientists as well as the general public for several reasons.

To start with, nobody is expecting a behemoth that’s up to 25 feet long to come so close to the California coast, said Paig-Tran.

“What’s special about them is that when they’re freshly dead or just about to die and you look at their skin, it actually [looks] like a mirror,” she said.

Its length combines with its silver skin and bright red scarlet fins to give it a mythical look.

Since the 1500s, sailors have told of sea monsters as long as their ships, and have even drafted maps that warned of areas in the ocean where such creatures resided. Their depictions appear to describe oarfish.

Oarfish generally live in the upper layers of the ocean depths, from about 300 feet to almost 3,000 feet underwater. Scientists call this section of the ocean the “twilight zone” because the fish that inhabit it are basically living in darkness with only a small glimpse of light, Paig-Tran said.

The twilight zone is too deep for divers to reach and explore, adding to the allure of this species.

If an oarfish happens to swim up to the ocean’s surface, a sailor would see a long slithering creature with spiky protrusions on its head and could believe it was a sea monster, Paig-Tran said.

It’s a jarring sight, but oarfish are anything but dangerous. Oarfish are bottom feeders, meaning they primarily feed on krill (a small shrimp-like creature) using powerful mouths shaped liked vacuum nozzles, according to Scripps.

An oarfish’s body is extremely delicate, so much so that if you pick one up it could break in half because of its jelly-like bones, Paig-Tran said.

Another factor that adds to the mystique of this creature is the lack of knowledge about its history and daily life, including how it mates, when it lays eggs, what its movement patterns are and how often it feeds.

Scientists are able to study the creatures only when they wash up on a beach.

“When a body comes up, we can do our best to look to the biology and the physiology and try to make our best guesses, but we don’t get to see it living in its natural environment,” Paig-Tran said. “It’s a completely open-ended question of what’s going on with these fishes.”

Why are dead oarfish washing ashore?

Scientists don’t know why these oarfish have died and washed ashore.

The latest oarfish spotted in Encinitas was recovered by a team of NOAA Fisheries Service and transported to Southwest Fisheries Science Center, where it will undergo an autopsy so researchers can learn more about the biology, anatomy, genomics and life history of oarfish, according to Scripps.

The deaths of the three fish that have surfaced “may have to do with changes in ocean conditions and increased numbers of oarfish off our coast,” said Ben Frable, manager of Scripps Oceanogaphy Marine Vertebrate Collection.

“Sometimes it may be linked to broader shifts, such as the El Niño and La Niña cycle, but this is not always the case,” he said.

There was a weak El Niño earlier this year, and this wash-up coincided with the recent red tide and Santa Ana winds last week. But many other factors could have played a role in these strandings, Frable added.

Another possible explanation is that the oarfish got stuck in a current and couldn’t go back down into deeper waters.

Oarfish aren’t strong swimmers. They primarily rely on their dorsal fin, whereas strong swimmers use their caudal fin or back tail, Paig-Tran said.

An oarfish that gets caught in a current and is taken up to the surface doesn’t have a good way to get back down.

“If you are a fish that lives in the deep and you got stuck on the surface, you’re kind of hosed,” she said.

Where did the “doomsday” name come from?

Oarfish have been dubbed “doomsday” fish because some cultures consider it a bad sign when they appear. The moniker is derived from a manipulation of Japanese folklore that became popular following the Fukushima disaster, Frable said.

“In the two years prior to the disaster, about a dozen oarfish washed up in Japan, most hundreds of miles away from this area.” he said.

In the aftermath of the natural disaster, people latched onto these strandings as an omen of the disaster.

This prompted researchers in Japan in 2019 to test whether oarfish and other deep-sea animal strandings were correlated with earthquakes, tsunamis and other factors.

“They found no correlation whatsoever,” Frable said. “But the name is too evocative to disappear.”

On the other hand, Paig-Tran said there could be some truth to the myth because when an earthquake happens, it releases pressure that can change a current underwater.

“When the pressure gets released, it changes the currents that [the fish are] living in, and it brings them up to the surface with this kind of big bolus of air and gasses and whatever the turbulence [is] from this earthquake,” she said.

So, are the oarfish that surfaced in Southern California a harbinger of a massive earthquake? According to Paig-Tran: probably not.