Strongest atmospheric river yet slams California with deadly impacts

Millions of storm-weary people across California faced another round of life-threatening weather to start the week as an atmospheric river unloaded more than a month's worth of rain in one day, which sparked flash floods, rockslides and avalanches.

The early-week storm is the latest of a line of storms that have pummeled California since New Year's Eve. More than a dozen storm-related fatalities have been reported across the state since the end of 2022, which is higher than the death toll from wildfires in California over the past two years.

At least four storm-related deaths were reported from the latest system, including one woman who was killed Monday in Avila Beach, located 150 miles northwest of Los Angeles, after her vehicle was overtaken by water. Two more fatalities were confirmed Tuesday after a large tree fell on two vehicles on Highway 99 near Visalia, California, killing both of the drivers.

On Wednesday, the Sonoma County Sheriff's Office reported the fatality of 43-year-old Daphne Fontino, who was found in a submerged vehicle in Forestville, California, with the vehicle approximately 8-10 feet deep in water when found by Marine Unit deputies.

A 5-year-old boy is also missing after he was swept away by floodwaters Monday near San Miguel, located 130 miles southeast of San Jose. The San Luis Obispo County Sheriff's Office said in a statement Tuesday evening that the search for Kyle Doan had concluded due to low visibility but would resume first thing Wednesday morning. When the search continued Wednesday, over 100 California National Guard members were aiding the search efforts, along with soldiers with the 270th Military Police Company.

"Our message to Californians is simple: be hyper-vigilant," California Gov. Gavin Newsom said. "There are still several days of severe winter weather ahead and we need all Californians to be alert and heed the advice of emergency officials."

AccuWeather issued a preliminary estimate on the total damage and economic loss from the parade of intense storms slamming into California to be between $31 billion and $34 billion on Wednesday.

President Joe Biden approved an emergency declaration for California Monday as the newest storm slammed into the state, a move that will allow the federal government to assist with disaster relief and emergency resources across the Golden State.

Santa Cruz, a coastal city about 60 miles south of San Francisco, experienced some of the worst of the flooding on Monday, which prompted mandatory evacuations in flood-prone areas. Downed trees and rockslides made roads impassable with local officials urging residents to stay at home if they weren't under evacuation orders.

"I've never seen anything like this," Santa Cruz resident Dianne Dias told AccuWeather National Reporter Bill Wadell on Monday. Dias has been a lifelong resident of Santa Cruz and lived through the 1955 flood, an extreme event in which she lost her house.

Dias expressed concern for the unhoused individuals living in the area since many were residing on hillsides where it is not safe to be amid the extreme weather conditions.

"I don't know where these people are," Dias said. "It's like they just disappeared."

Santa Cruz resident Dianne Dias talks about the historic flooding that took place across the region on Monday, Jan. 9, 2023. (AccuWeather/Bill Wadell)

Farther south, an evacuation order was issued for all of Montecito, California, due to the risk of flooding and mudslides. The seaside town is home to A-list celebrities, including Ellen DeGeneres, who captured a video of a creek that "never flows" that was transformed into a raging river. "Stay safe everybody," DeGeneres added. DeGeneres noted that since her home sits on higher ground, she was told to shelter in place, rather than evacuate.

A two-day rainfall total of 8.07 inches was measured near Montecito, which is more than double the 3.84 inches of rain that typically falls in the area in all of January.

Monday's extreme flooding occurred on the five-year anniversary of deadly mudslides in Montecito that claimed the lives of 23 individuals and damaged hundreds of homes. The historic mudslide occurred after heavy rain fell on a burn scar from the Thomas Fire, one of the largest wildfires in California history.

Southeast of Montecito in Ventura County, a mudflow slammed into cars on Casitas Vista Road, forcing officials to close the road. Fortunately, no one was injured in the mudslide.

Four people had to be rescued from a 15-foot sinkhole after a flooded road collapsed in the Los Angeles neighborhood of Chatsworth on Monday evening, swallowing two vehicles. The two occupants of a pickup truck were able to climb out of the sinkhole. Two others, a woman and a young girl, in another vehicle were rescued by about 50 firefighters who used a high-angle rope and an aerial ladder.

Andrew Wordin, the Los Angeles Fire Department battalion chief, said both the young girl and woman were transported to a hospital with minor injuries. Both vehicles remained in the sinkhole as of Tuesday. The road will remain closed for an "undetermined duration" while city officials evaluate and determine the repairs needed, ABC7 reported.

While some of the worst conditions and highest rainfall amounts were reported along the California coast, areas farther inland also experienced heavy rain and bouts of severe weather.

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State Route 168 near Fresno was one of many roads that were closed after a rockslide blocked both lanes. A dramatic video from crews at the scene captured massive boulders larger than vehicles careening down a mountainside before coming to rest in the middle of the road.

Californians were jolted awake by weather alerts Monday night as severe thunderstorms rumbled through the Sacramento area. Two tornado warnings were issued south of the state capital, including one tornado warning in Stockton and another in Modesto. These were the first tornado warnings issued by the National Weather Service Office in Sacramento since April 21, 2022.

The weather radar near Sacramento, California, around 4 a.m. PST Tuesday, Jan. 10, 2023. The yellow box indicates a severe thunderstorm warning. The black boxes indicate tornado warnings. (AccuWeather)

Higher up in the Sierra Nevada, the atmospheric river unloaded feet of snow that shut down mountain passes. Donner Pass remained open to traffic throughout most of the storm, although chains were required during the height of the snow. State Route 88 at Carson Pass, located 17 miles south of Lake Tahoe, was closed not just due to snow, but also due to the risk of avalanches.

One person was killed in an avalanche on Mount Charleston, Nevada, located 30 miles northwest of Las Vegas, on Monday, according to KLAS. The area received nearly a foot of snow from the same system that was walloping California.

Hurricane-force wind gusts were clocked in the higher elevations in California, including a 115-mph wind gust at Mammoth Mountain and a 127-mph wind gust at Palisades-Tahoe.

Winds were not as intense in the lower elevations, but gusts were still strong enough to blow over trees with roots in waterlogged soil. Downed trees contributed to the more than 220,000 power outages across the state on Tuesday, according to PowerOutage.us.

The stormy pattern is showing no signs of letting up anytime soon with another storm set to drench the West Coast through Thursday.

AccuWeather meteorologists are forecasting the next system to track farther north than the early-week storm, with the heaviest rain and mountain snow predicted to fall across Northern California and Oregon. This is good news for areas of Central and Southern California that need a break from the flooding and mudslides, but the pause in precipitation will not last long.

"More precipitation is expected to spread across the majority of California again on Saturday," AccuWeather Meteorologist Joseph Bauer said.

The weekend storm is likely to cause more flooding and mudslides across the state, including regions that were hit hard Monday and Tuesday.

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