Lingering atmospheric river soaks California, threatens more flooding, mudslides

Reuters

As rain continued to fall throughout Los Angeles, work crews and residents were cleaning up after the storm felled more than 250 trees and triggered 380-plus mudslides across the nation's second-largest city as of Monday night, authorities said.

By Steve Gorman and Jane Ross

LOS ANGELES (Reuters) - A deadly atmospheric river storm lingered over Southern California for a third day on Tuesday, soaking the region with steady rains that threatened to trigger more flooding and mudslides as the weather system slowly crept toward the Desert Southwest.

After a day of record-breaking rainfall across the Los Angeles area, a flood watch remained in effect for much of Southern California through Tuesday afternoon. A flash-flood warning was posted for the Orange County coast, and flood advisories were issued as far south as San Diego and the U.S.-Mexico border.

As rain continued to fall throughout Los Angeles, work crews and residents were cleaning up after the storm felled more than 250 trees and triggered 380-plus mudslides across the nation's second-largest city as of Monday night, authorities said.

CALIFORNIA/REUTERS/Mike Blake

Workers begin to clean up debris from a storm that continues to impact Oceanside, California, U.S., February 6, 2024. REUTERS/Mike Blake

Downed trees and utility lines knocked out electricity to hundreds of thousands of homes and businesses, including 156,000 utility customers who remained without power in Los Angeles alone as of Tuesday.

L.A. Fire Chief Kristin Crowley said at least three dozen buildings required inspection due to mudslide damage and hillside slope failures. Seven have been red-tagged as unsafe for occupancy.

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"Even though the rain may ease up a bit today, this storm continues, and that means we still need Angelinos to take precautions," Mayor Karen Bass told a news conference.

'Once-in-a-lifetime scenario'

Barry Blocker, 55, a retired police officer, said he spent several hours on Monday digging his car out from a cascade of mud that had poured down a hillside onto his driveway before dawn. The house where he has lived in L.A.'s Baldwin Hills district for 23 years without incident was undamaged.

EXPLAINER: What is a 'Pineapple Express'?

"Hopefully, it's a once-in-a-lifetime scenario," he said on Tuesday has he stood in his garage, still cleaning up water and muck from the aftermath.

Prolonged downpours that dumped 6-12 inches (15-30 cm) of water have left the ground so "super-saturated" that it will take very little additional rain to trigger further landslides and debris flow, said Ariel Cohen, chief forecaster for the National Weather Service (NWS) office in Los Angeles.

CALI FLOODING/REUTERS/Aude Guerrucci

Cars drive on flooded streets, during the ongoing rain storm in Studio City, California, U.S., February 5, 2024. (REUTERS/Aude Guerrucci)

The intense rainfall, with heavy snows in the mountains, was carried to California by a storm system meteorologists call an atmospheric river, a vast airborne current of dense moisture funneled inland from the Pacific.

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The latest tempest, and a less powerful storm that hit California last week, also qualified as a "Pineapple Express," a type of atmospheric river originating from subtropical waters around Hawaii.

While such storms are not uncommon to the West Coast, meteorologists say they are likely to become more frequent and extreme over the next century if planetary warming from human-induced climate change continues at current rates.

REUTERS: Rain falls over cars stuck by a mudslide, caused by an ongoing rain storm in Studio City, California, U.S., February 5, 2024. REUTERS/Aude Guerrucci

Rain falls over cars stuck by a mudslide, caused by an ongoing rain storm in Studio City, California, U.S., February 5, 2024. (REUTERS/Aude Guerrucci)

Scientists say the prevailing El Nino weather pattern also may be contributing to some of the recent storm activity along the Pacific coast.

The latest storm kicked off in California with powerful winds gusting to 75 miles per hour (121 kph) and higher across northern and central California on Saturday, before spreading into South California early on Sunday.

At least three people were killed when wind toppled trees on Sunday in Sacramento, Santa Cruz and Sutter counties, authorities said.

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While diminishing rain and thundershowers were expected to loll over the greater Los Angeles and San Diego areas Tuesday, increasing precipitation was forecast for the California desert and Colorado River Basin as the storm front drifts into Arizona.

CAL FLOODING/REUTERS/Aude Guerrucci

The remains of a home destroyed by a mudslide caused by the ongoing rain storm in Los Angeles, California, U.S., February 5, 2024. (REUTERS/Aude Guerrucci)

In Los Angeles, the onslaught will linger in the record books as one of the wettest storms in more than 150 years, meteorologists say, as well as in the minds of those who experienced it.

"To see the way that the land can just so quickly shift and come apart, it's so weird to think that it could come down onto where people live," Deborah Puette, an actor and filmmaker living in L.A.'s Studio City neighborhood, said outside a nearby home crumbled by a mudslide.

"Living in Southern California, we have it pretty easy in general, so major weather events like this, they're unusual and they're intense."

WATCH | Science behind 'Pineapple Express' storms:

Thumbnail courtesy of REUTERS/Aude Guerrucci.

(Reporting and writing by Steve Gorman in Los Angeles; Additional reporting by Jane Ross in Los Angeles, Brendan O'Brien in Chicago and Julia Harte in New York; Editing by David Ljunggren and Sandra Maler)