Landslides and severe flooding were reported in Los Angeles on Sunday night, as a storm that reached Southern California after battering northern parts of the state was forecast to bring more heavy rain and winds for another day.
“The biggest wind and power outages will be the less dangerous part of the storm, compared to what will happen, and is starting to happen, in Southern California,” Dr. Daniel Swain, a climate scientist at the University of California, Los. Angeles, he said during an online briefing Sunday night. “If you’re worried about the north, I’m more worried about the south and what’s to come.”
They were mudslides on all canyon roads in and out of Malibu, according to the Los Angeles County Sheriff’s Department. And in the Studio City neighborhood, firefighters evacuated six people from two homes as water dragged debris into the area, the Los Angeles Fire Department said. Officials warned that the worst was likely yet to come, with heavy rain expected for at least the next 24 hours.
The danger, they said, wasn’t primarily from wind blowing down power lines or trees (although thousands were without power Sunday night). Instead, the danger came from the path of an atmospheric river, a huge plume of moisture, which forecasters said was expected to stall in one of the country’s most populous regions.
“I don’t think the rain will stop for the next 24 to 36 hours,” said Dr. Swain earlier on Sunday.
On Sunday, meteorologists and officials urged Los Angeles residents to prepare for flooded streets in the valleys and landslides in the mountains. The entire county, home to nearly 10 million people, was under a flood warning until midnight.
As of Sunday evening, more than four inches of rain had fallen in the Santa Monica Mountains, with rain totals rising at a rate of more than half an inch per hour, according to Joe Sirard, a meteorologist with the National Weather Service in Oxnard, north of Los Angeles.
And when rain falls in large amounts in the mountains, it rushes downhill, sometimes taking saturated soil with it, and collects in low-lying areas, such as large swathes of the San Fernando Valley, leaving intersections and streets under water. Rivers and streams could swell, overflow their banks and flood the surrounding neighborhoods.
“Many, many hours of rain add up,” Sirard said.
Soumya Karlamangla contributed to the reporting.