California Atmospheric River Update as Evacuation Warning...

By Anna Commander

Deputy News Editor

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Areas of Southern California are under an evacuation warning amid a risk for potential mudslides and debris flows as a strong atmospheric river hits the region.

Newsweek reached out to the National Weather Service (NWS) via email on Thursday for comment.

Why It Matters

California is enduring an intense atmospheric river storm this Christmas holiday, putting millions of residents on alert for possible flooding, mudslides and power outages. The NWS and state emergency authorities have issued evacuation orders and warnings, particularly in regions affected by previous wildfires where soil instability is elevated. The storm exemplifies the ongoing struggle California faces balancing drought and extreme weather, potentially straining emergency response systems, infrastructure and travel during one of the busiest times of the year.

What To Know

An atmospheric river storm—essentially a narrow corridor of concentrated moisture—has swept across California, impacting the state with rain, high winds and flash flooding warnings. Southern California saw the heaviest effects starting Wednesday as the NWS issued flash flood, high wind and winter storm warnings from Los Angeles to Shasta Counties. In Los Angeles, rain totals could reach up to 8 inches—two to three times the usual December levels.

According to the San Bernardino County Sheriff's Office, the Wrightwood and Lytle Creek communities are under an evacuation warning. Numerous other communities including Forest Falls, Seven Oaks, Angelus Oaks, Northeast Yucaipa and areas of Oak Glen were also under an evacuation warning on Thursday, but they have since been lifted.

The sheriff's office posted an interactive map for residents in the area to check for evacuation updates.

The NWS warns, "Additional atmospheric river surge to impact central and southern CA going into the evening hours. Locally heavy rainfall rates coupled with extremely sensitive conditions on the ground from previous rainfall will promote additional areas of flash flooding with locally dangerous and life-threatening impacts possible."

Heavy snow over the Sierra Nevada and north California mountains is also possible, the NWS says.

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What People Are Saying

Democratic California Governor Gavin Newsom, on X Wednesday: "With atmospheric rivers, intense rainfall, and strong winds ahead, I’m declaring a state of emergency in Los Angeles, Orange, Riverside, San Bernardino, San Diego, and Shasta counties to activate emergency authorities and preposition resources to keep our communities safe."

LA City Emergency Management Department, on X Thursday: "Don't let the LULL between storms trick you into thinking we're 'olly olly oxen free' from the rains. @NWSLosAngeles expects 'two more impulses' to move through @LACity areas today & Friday bringing periodic showers & a chance of thunderstorms. Flooding potential remains high."

What Happens Next

Officials stress that even after precipitation subsides, hazards like power outages, debris flows, and road closures may persist. The NWS forecasts that heavy rain and flooding threats will remain in place on Thursday.

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