An early season atmospheric river that brought powerful winds, heavy downpours, flooding and even tornado warnings to Southern California was also a significant test for the region’s burn scars ahead of its traditional rainy season.
The storm — Los Angeles’ first significant rain of the water year that began on Oct. 1 — dumped 2.17 inches of rain in Bel-Air, 2.10 inches in Beverly Hills, 1.27 inches in downtown Los Angeles and 3.28 inches in Woodland Hills as of Tuesday afternoon. The last time downtown got more than an inch of rain in a single day in October was 2009, said John Dumas, a meteorologist with the National Weather Service in Oxnard.
Opids Camp, perched at the top of the San Gabriel Mountains, received the biggest soaking, with 5.53 total inches of rainfall.
The storm, classified as a weak, or Level 1, atmospheric river, brought enough moisture to Southern California’s drought-stricken landscape to delay fire season for weeks, if not months, said Marty Ralph, director of the Center for Western Weather and Water Extremes at UC San Diego’s Scripps Institution of Oceanography.
And it did so without disintegrating the hills ravaged by January’s Palisades and Eaton fires into large flows of rock, mud and debris, Ralph said.
“In a way this is like a Goldilocks atmospheric river,” Ralph said. “It’s sort of just right to be mostly beneficial at this stage of the year.”
Evacuation warnings in Los Angeles-area burn scars, which were initially set to expire at 6 a.m. Wednesday, were instead lifted at 6 p.m. Tuesday due to improving weather conditions.
“City crews and public safety officials rapidly mobilized to prepare for this weather event and to respond to any potential emergencies — their work kept Angelenos safe, especially as it relates to burn scar areas,” L.A. Mayor Karen Bass said in a Tuesday evening statement.
Officials were most concerned about those burn scars in Pacific Palisades, Altadena, Sylmar and the Hollywood Hills.
Burned soil repels water instead of soaking it in, so it takes less rain to trigger damaging flooding and debris flows, Dumas said.
On Monday, Los Angeles city and county authorities worked to prepare vulnerable areas with sandbags, and law enforcement went door to door warning residents to prepare to evacuate if necessary. The Los Angeles Fire Department, in coordination with the state Office of Emergency Services, pre-deployed a 22-person strike team, a 27-member hand crew, a six-member urban search-and-rescue team and a 16-member swift-water rescue team to respond to potential debris flows.
On Tuesday, an evacuation order encompassing nearly 115 properties within the burn scars of the Palisades, Sunset and Hurst fires was put into effect. In Orange County, strong downpours prompted officials to issue evacuation orders for some areas below the Airport fire burn scar from last year.
No significant damage in those areas had been reported by the afternoon. Evacuation orders in Orange County were lifted by 5 p.m., officials said.
The storm arrived just two weeks after Marquez Elementary reopened in Pacific Palisades, a milestone seen by many as a step toward reviving the fire-scarred community. But Tuesday, students and teachers were forced to relocate to another school on the Westside because of possible landslides in the neighborhoods around the campus.
The return to Marquez had been widely celebrated among families and staff, but some had criticized the return to the site as premature.
“What does this look like if we have a wet winter?” parent Andrea Samulon said in an email to The Times. “How many days of school will these kids end up losing? … These are the obvious and predictable repercussions of the hasty return to a community that hasn’t even begun to recover from the fire.”
For all the problems the storm caused, it may have helped stave off others, experts say.
Trees, grasses and plants that make up Southern California’s natural landscape will absorb a lot of moisture from the rain, making them less prime to burn — at least for a while.
“It doesn’t take very many AR storms to really help us have a normal water year and recover from drought,” Ralph said. “This is starting the season off on a favorable foot.”
If another storm arrives in the next few weeks, it could stave off the wildfire season even further, Ralph said. But if the rest of the fall season is dry and Santa Ana winds kick up, that brush could dry out again, raising concerns about fires.
But in the near term, the storm created its fair share of damage and traffic headaches Tuesday.
At about 10:30 a.m. firefighters rescued a 30-year-old woman, a 45-year-old man and two dogs from a platform along the Los Angeles River, according to LAFD.
The man was taken to a hospital for mild cold exposure. The woman declined to be taken to a hospital, LAFD said.
In Orange County, sheriff’s officials and firefighters were attempting to retrieve what they believed was a body found floating along the Santa Ana River Tuesday afternoon.
The suspected body was first seen along the river near the 405 Freeway in Fountain Valley around 11 a.m. and has since moved toward Adams Avenue in Huntington Beach, said Sgt. Gerard McCann with the Orange County Sheriff’s Department.
In Sun Valley, heavy rain accumulation caused the flat roof of a movie studio to collapse, causing damage to film equipment and sets, according to the weather service. A woman who was inside the building at the time told Fox 11 Los Angeles that she heard what she thought were heavy footsteps on the roof before water started pouring into the studio.
Along with the heavy rain, the storm unleashed strong winds with gusts reaching 53 mph at Zuma Beach in Malibu, 45 mph along the Newhall Pass and up to 73 mph in portions of the Western San Gabriel Mountains, according to the weather service.
The storm began in earnest before sunrise, moving through San Luis Obispo County around midnight and dropping up to 2.5 inches of water per hour. It prompted the weather service to issue a couple of rare tornado warnings for areas including Pismo Beach, Nipomo and Oceano, but it wasn’t immediately clear whether a tornado formed.
The storm then moved down into Ventura County’s mountains later Tuesday morning, where some higher-elevation areas saw rainfall rates as high as 3.5 inches per hour, Dumas said. Downed trees, rocks and debris were reported, he said.
Roadway flooding was reported across Los Angeles and Ventura counties, including on Hueneme Road near Olds Road in Mar Vista, along the 101 Freeway near Seward Avenue in Ventura and along the 5 Freeway near Sheldon Road in Sun Valley. In Lake Hughes, rocks and mud were strewn across a portion of San Francisquito Road. In Encino, a downed tree was blocking a lane of Burbank Boulevard.
Before arriving in Southern California, the wintry storm swept through Northern and Central California, where it dusted the Sierra with the season’s first major accumulation of snow, caused flight delays at San Francisco Airport, and generated a whirling column of air and mist over Monterey Bay. By Monday evening, rainfall totals in the Bay Area ranged from around 0.5 inches to 2 inches, according to the weather service.
Lingering showers are expected to peter out by Wednesday evening, with drying and warming winds sweeping across the county that night. Southern California’s characteristically moderate climate should return by Thursday with pleasant highs in the 70s common across L.A. County.
Times staff writer Howard Blume contributed to this report.