Most Californians under severe weather alert as another atmospheric river dumps heavy rain

ByNouran Salahieh and Christina Maxouris, CNNWire
Tuesday, March 21, 2023
Atmospheric river causes heavy rain, extreme weather in California
Most of California is under a severe weather alert amid snow and another atmospheric river dumping heavy rain.

CALIFORNIA -- California state emergency officials have deployed crews across the state to respond to the potentially damaging impacts of yet another atmospheric river that is slamming the storm-fatigued state, CNN reported.

More than 35 million Californians -- most of the state's population -- were under some kind of weather alert Tuesday afternoon.

Powerful winds, thunderstorms and showers were impacting most of central and Southern California Tuesday. In Los Angeles, weather officials reported strong wind gusts ranging between 40 and 50 mph and warned more heavy rain was on the way later in the day.

State transportation officials reported snow and windy conditions in the mountains of Southern California's Riverside and San Bernardino counties. Officials recommended residents in the area maintain at least a two-week supply of food, water, medication and fuel ahead of the rapidly strengthening storm's arrival.

"Visibility is at a big 'nope' today," the state transportation department for the region wrote on Twitter. "Please consider travel when conditions are more favorable. If you must travel, be prepared and stay safe."

The heavy rain and snow could worsen conditions for communities still flooded from the previous atmospheric river that pummeled the state -- and ended just days ago.

California has already seen at least 12 atmospheric rivers this winter season that ravaged communities, displaced residents and prompted emergency declarations as floodwater inundated neighborhoods, swelled rivers, damaged roads and sent mud and rocks sliding down hills.

"Now's the time to ensure you and your family are prepared," officials from the California Governor's Office of Emergency Services urged residents Tuesday.

Swift-water rescue teams, hand crews and bulldozers were also stationed in counties throughout the state.

"This is going to be yet another challenging event -- probably not an extreme storm individually by historical standards -- but once again, another significant event that, on top of everything that has come before, it's going to cause some major problems," UCLA climate scientist Daniel Swain said in a video.

More rain than normal in California

It's unclear how the climate crisis could be influencing the number of storms that hit the West Coast, but scientists have linked it to an increase in the amount of moisture the atmosphere holds. That means storms, like these atmospheric rivers, are able to bring more moisture inland, leading to an increase in rainfall rates and flash flooding.

Since October 1, Los Angeles has received more than 24 inches of rain - roughly twice as much as it normally gets for this time period. That's also about 10 inches above their annual average, as the vast majority of California's rainfall occurs from late fall to early spring.

And it's not just Los Angeles: cities across the state are seeing very similar numbers.

San Francisco, Oakland, Sacramento, Stockton and Fresno have all seen 150 to 200% of their normal rainfall since October 1.

While the extreme rainfall has triggered flash flooding, mudslides and caused damage, it has also significantly increased critical state reservoirs including Lakes Shasta and Oroville, which have risen by more than 100 and 180 feet respectively since December.

What to expect this week

The widespread rain, mountain snow and strong winds across parts of central and Southern California will continue Wednesday and will gradually clear up Thursday, said National Weather Service Meteorologist Sarah Rogowski.

The heaviest impact will likely be felt in southern California, which could see around 1 to 3 inches of rain across lower elevations and 2 to 4 inches across the foothills through Thursday.

The Weather Prediction Center raised the flood threat to a moderate level Monday for areas of Southern California, covering more than 15 million people in coastal areas from Los Angeles to San Diego.

Soils are still overly saturated with water from last week's storms, setting the stage for more flooding and rapid runoffs.

SEE ALSO | Caught on video: Crews rescue man from rain-swollen Los Angeles River in Southern California

The powerful storm could also lash Southern California with maximum wind gusts near 75 mph, adding the dangers of fallen trees and powerlines to the mix of hazards Californians are facing this week. More than 30 million people are under alerts for strong winds from California into Nevada and Arizona.

In the Sierra Nevada and Southern California mountains, as much as 3 to 4 feet of snow could be piled on top of already buried communities, likely straining infrastructure and making travel difficult, the weather service said.

Thousands were evacuated from two small central California towns, Alpaugh and Allensworth, in Tulare County, where there have been multiple breaches in waterways and repair efforts were "unsuccessful with the amount of water," Tulare County Sheriff Mike Boudreaux said.

Officials worried roads could become impassable and isolate residents, and deputies went door-to-door before dawn Monday asking people to flee.

So far, seven structures were destroyed and more than 680 were damaged by floods in Tulare County, according to Cal Fire.

Crews prepare for mudslides and mountain snow

Amid fears over mud and debris flows from the El Dorado and Apple fire burn scars in San Bernardino County, an evacuation warning was issued for the communities of Oak Glen, Forest Falls, Mountain Home Village, Angelus Oaks and Northeast Yucaipa.

With more rain on the way, protecting people near vulnerable wildfire burn scar areas is among the top concerns for crews.

Scorched soil can't absorb rain at a normal rate, making it unstable, explained Yucaipa Fire Chief Grant Malinowski, who is part of the operations group keeping watch over the El Dorado burn scar.

RELATED | Severe weather threatens 25M Americans; storm system pounds CA with hurricane-force winds, flooding

The fear is that mud and debris could slide down, make roads impassable, damage homes and strand people, Malinowski told CNN.

Firefighters across the state have been stationed around burn scars each time an atmospheric river menacingly takes aim at the state -- and they've been doing it a lot this winter season.

"It's kind of like almost like fire season right now," Malinowski said, describing thousands of firefighters and crew members from Cal Fire and the National Guard throughout the state responding to recent storms.

But unlike with wildfires, residents could have less time to get away from mudslides.

"It's not like a fire where they can see the fire building and getting closer. This is instantaneous. It just happens and it's too late for you to react to it," Malinowski said.

And performing rescues in mudslides is no easy task -- so it's important for residents to obey evacuation orders, which aren't made lightly, Malinowski said.

"We understand the gravity of asking people to voluntarily leave their homes, but it's also weighed with the ability for us to rescue people, knowing that it's going to be a very difficult -- if not impossible -- task to get through just tons of tons of dirt and debris where we just literally can't make access," Malinowski said.

Up in the mountains, the concern is heavy snow stranding people.

SEE MORE | California flooding: New storm threatens to bring heavy rain to places still covered in snow

"The storm is expected to peak on Tuesday and Wednesday and dump as much as three feet of additional snow on mountain communities that were hit with as much of 10 feet of snow during storms in late February and early this month," San Bernardino County officials said.

The county said it is activating public works employees for 24-hour snow plowing and storm patrol, having County Flood Control District crews active on split shifts during the storm and adding additional sheriff deputies to routine patrols for the next two weeks.

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