Rainfall from one of the wettest storms in southern California history was to ease off on Tuesday, but forecasters warned that floods were still possible and soaked ground raised the threat of potentially deadly landslides.
The slow-moving storm that parked itself over the region on Monday, dumping a record amount of rain on parts of Los Angeles, could linger into Wednesday, the National Weather Service said. Scattered showers and some possible thunderstorms would bring light to moderate rain, but there was still the threat that many places could see brief, fierce downpours dumping 0.5 to 1in ( 1.3 to 3cm) of rain in an hour.
Authorities warned people to remain on high alert and most of southern California remained under flood watches. Swollen and fast-moving creeks and rivers “increase the risk for drowning and the need for swift water rescues”, the weather service said.
The storm plowed through northern California over the weekend, killing three people who were crushed by falling trees, then lingered over the south. It was the second storm fueled by an atmospheric river to hit the state over the span of days.
On Monday, it deluged Los Angeles with rain, sending mud and boulders down hillsides dotted with multimillion-dollar homes, turning streets into rushing rivers. Some residents rushed to evacuate and people living in homeless encampments in many parts of the city scrambled for safety.
Near the Hollywood Hills, floodwaters carried mud, rocks and household objects downhill through Studio City, city officials said. Sixteen people were evacuated and several homes were red-tagged.
“It looks like a river that’s been here for years,” said Keki Mingus, whose neighbors’ homes were damaged. “I’ve never seen anything like it.”
The storm has produced alarming amounts of rain so far, with some areas of Los Angeles totaling more than 10in (25cm). The University of California, Los Angeles, located on the west side of the city, received more than 11.8in (30cm) – more than three times the average amount that falls in the entire month of February, the UCLA climate scientist Chad Thackeray reported.
Clothes, books and even refrigerators cascaded down roads alongside debris pulled from damaged homes, and the tony Beverly Crest neighborhood was inundated with mud after two landslides converged on the area.
Early Monday morning, the NWS station in Los Angeles warned that an “extremely dangerous” situation was unfolding in the Santa Monica mountains and the Hollywood Hills. Fox 11 said a resident on Caribou Lane had told the station that “the whole hillside came down, shoved the house into our road here and up against our neighbor’s porch and driveway, and it trapped a few people”.
“We looked outside and there’s a foot-and-a-half of running water, and it starts seeping through the doors,” said Drake Livingston, who was watching a movie around midnight when a friend alerted him to flooding. His car was submerged in mud by Monday morning.
The danger was not over despite a projected dip in the rainfall, warned Ariel Cohen, the meteorologist in charge of the National Weather Service bureau in Los Angeles.
“The ground is extremely saturated, supersaturated,” he said at a news conference. “It’s not able to hold any additional water before sliding. It’s not going to take much rain for additional landslides, mudslides, rockslides and other debris flows to occur.”
In LA, an evacuation order remained in place for some residents of a canyon area that was scarred by a 2022 fire. The area was at increased risk of mud and debris flows because the area was burned bare of brush and trees that could hold it back, authorities said.
The Los Angeles fire department said 1,000 firefighters had dealt with more than 300 mudslides in addition to more than 100 reports of flooding and rescues of motorists stranded in vehicles on inundated roadways.
Shelters added beds for the city’s homeless population of nearly 75,000 people.
Among those who died were two men killed by fallen trees on Sunday in Carmichael, a suburb of Sacramento, and in Boulder Creek in Santa Cruz county. Police were investigating the death of another man in Yuba City, about 100 miles (160km) north-east of San Francisco, who was found under a redwood tree in his backyard.