The powerful atmospheric river that brought record amounts of rain to California and led to nearly 400 mudslides in recent days began to ease on Tuesday, but forecasters said the risk for floods and landslides remained.
The intense weather left a trail of destruction as it made its way across the state, with violent winds and rain causing downed trees and destructive mudslides that damaged homes and buried vehicles. At least three people were killed by falling trees.
The slow-moving storm parked itself over southern California on Monday, dumping a historic amount of rain on parts of Los Angeles. Downtown Los Angeles received 2.93in (7.44cm) of rain on Monday, surpassing a record for the day set in 1901.
The National Weather Service (NWS) said more than 10in (25cm) of rain had fallen since Sunday across the Los Angeles area, the nation’s second-largest city, with much more expected before the downpour was due to taper off later in the week. The city’s mayor, Karen Bass, described it as a “historic storm” with “unprecedented rain”.
Nearly a foot of rain was measured over a 24-hour period on the campus of the University of California at Los Angeles (UCLA).
“We’re talking about one of the wettest storm systems to impact the greater Los Angeles area” since records began, Ariel Cohen, chief NWS meteorologist in LA, told an evening news conference. “Going back to the 1870s, this is one of the top three.”
Southern California was expected to see scattered showers and some possible thunderstorms with light to moderate rain on Tuesday, 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.
Firefighters across southern California rescued people from rivers and flooded roads in recent days. The Los Angeles fire department said 1,000 firefighters had dealt more than 100 reports of flooding and rescues of motorists stranded in vehicles on inundated roadways, including a dog and its owner pulled from the LA river. Crews reported rescuing 16 people and five cats in LA county, authorities said.
The storm first 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 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.
The atmospheric river is so far projected to have caused as much as $11bn in damage and economic losses, according to a preliminary estimate from Accuweather.
The danger was not over despite a projected dip in the rainfall, warned Cohen.
“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.”
Crews have responded to 383 mudslides since the storm began, and seven buildings have been deemed uninhabitable, officials said.
The city’s emergency shelters were full, Mayor Bass said on Wednesday. The city does not yet have the total number of homes that were damaged by the storm.
As the storm hovered over LA, 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.
Associated Press contributed reporting
