An intense atmospheric river struck Los Angeles early Tuesday morning, resulting in scattered downpours, powerful winds, and significant flooding concerns, alongside some rare tornado warnings particularly in areas along the Central Coast.
Officials have issued evacuation warnings for regions severely affected by the firestorm in January, including burn scars from the Palisades fire, Eaton fire in Altadena, Hurst fire in Sylmar, and Sunset fire in the Hollywood Hills—areas that face a high risk of debris flows.
Currently, an evacuation order has been implemented, covering nearly 115 properties within the burn scars of the Palisades, Sunset, and Hurst fires, effective until 6 a.m. on Wednesday.
In Orange County, strong downpours led officials to issue evacuation orders for specific areas located below the Airport fire burn scar early Tuesday.
Around 10:30 a.m., firefighters conducted a rescue operation, saving a 30-year-old woman, a 45-year-old man, and two dogs from a platform along the Los Angeles River, according to the Los Angeles Fire Department (LAFD).
The man was assessed and taken to a hospital for mild cold exposure; however, the woman declined medical assistance.
Heavy rain accumulation resulted in the collapse of the flat roof of a movie studio located in Sun Valley, which led to damage to the film equipment and sets, as reported by the weather service.
A woman who was present in the building during the incident recounted hearing what she initially thought was heavy footsteps on the roof before water began to pour into the studio.
By mid-morning Tuesday, rain was falling heavily across the Palisades fire burn scar, and the National Weather Service issued a flash flood warning for the area, stating that rainfall rates could be intense—ranging from 1 to 1.5 inches per hour.
Meteorologist John Dumas explained that burned soil is less effective at soaking up water, making it more susceptible to flooding and debris flows with lesser rain amounts.
This flash flood warning also extends to the Franklin fire burn scar in Malibu.
Moreover, a severe thunderstorm warning was put in place for parts of west-central Los Angeles County until 9:30 a.m., indicating that a line of thunderstorms extending from Thousand Oaks to Westlake Village could generate hail and wind gusts of up to 60 mph, posing risks to roofs, siding, and trees.
A flash flood watch remains active for most of the county through Tuesday afternoon, with the heaviest rainfall anticipated for the morning.
The weather service has cautioned that this “rare and very potent storm system” carries with it threats of mudslides, thunderstorms, hail, and gusty winds capable of toppling trees and power lines.
Reports indicate that the storm began earnestly on Tuesday morning, causing rain to fall across Los Angeles and knocking down trees in locations near Balboa Avenue and the 101 freeway, as noted by the National Weather Service.
Numerous cases of roadway flooding have been reported across Los Angeles and Ventura counties, including incidents on Hueneme Road near Olds Road in Mar Vista, along the 101 freeway near Seward Avenue in Ventura, and on Interstate 5 near Sheldon Road in Sun Valley.
In Lake Hughes, rocks and mud have been cleared from portions of San Francisquito Road, while in Encino, a downed tree is blocking a lane on Burbank Boulevard.
Residents have been urged to consider seeking shelter indoors during this storm.
The weather service warned: “Torrential rainfall is also occurring with this storm and may lead to localized flooding. Do not drive your vehicle through flooded roadways.”
By 10 a.m., heavy rain began affecting central and south Orange County, causing officials to alert residents in communities near the Airport fire burn scar in the Santa Ana Mountains to be prepared for potential evacuation due to the risk of debris flows.
Mandatory evacuation orders were also issued for several regions, including Trabuco Creek and Bell Canyon, particularly Starr Ranch and Hot Springs Canyon, where the possibility of debris flows looms.
Meteorologist Adam Roser from the Weather Service in San Diego indicated that the worst of the storm was predicted to hit Orange County between 11 a.m. and 2 or 3 p.m., with rainfall rates possibly reaching 0.75 inches per hour.
The weather service noted that a flood watch remains in effect for burn scar areas and that a flood warning will follow if conditions worsen as rainfall intensifies.
The storm passed through San Luis Obispo County around midnight, dropping as much as 2.5 inches of rain per hour and prompting the weather service to issue rare tornado warnings for locations including Pismo Beach, Nipomo, and Oceano; it remains uncertain whether a tornado actually formed.
As the storm traversed Ventura County’s mountainous areas later on Tuesday morning, some higher-elevation sites reported rainfall rates up to 3.5 inches per hour.
Dumas reported that downed trees, rocks, and debris had emerged as significant concerns.
Prior to its arrival in Southern California, the wintry storm had swept through Northern and Central California, blanketing the Sierra Nevada region with the first major accumulation of snow for the season, causing flight delays at San Francisco Airport, and even generating a whirling column of air and mist over Monterey Bay.
By Monday evening, rainfall totals across the Bay Area ranged between 0.5 inches to 2 inches, according to the weather service, with road flooding reported throughout the area.
In Los Angeles County, predictions indicate total rainfall of 0.75 to 1.5 inches in coastal and valley regions and between 2 to 4 inches in foothill and mountainous areas.
These storm systems are also expected to cause regional temperatures to drop several degrees below normal.
Flash flood warnings are now in effect for much of Ventura County, parts of northern Santa Barbara County, and inland Orange County, with additional warnings for residents in burn scar areas to remain vigilant for debris flows.
The weather service shared that peak rainfall rates of 0.33 to 0.66 inches per hour are typically sufficient to cause road issues and generate heavy traffic during the Tuesday morning commute.
Additionally, rockslides in canyon roads are anticipated to be nearly certain given the conditions.
Earlier, Topanga Canyon Boulevard was closed between Pacific Coast Highway and Grand View Drive from 10 p.m. Monday until 5 a.m. Tuesday due to the predicted storm impacts.
This particular stretch, measuring 3.6 miles, is consistently undergoing repairs due to damage caused by the Palisades fire and previous winter storms.
City and county officials made preparations for vulnerable areas by distributing sandbags on Monday, while law enforcement conducted outreach, going door-to-door to advise residents about the risks associated with debris flows.
The Los Angeles Fire Department has coordinated with the state Office of Emergency Services to pre-deploy resources, including a 22-member 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.
Officials are strongly urging residents to sign up for emergency alerts at NotifyLA.org and to remain attentive to evacuation warnings.
In a statement released on Monday, L.A. County Board of Supervisors Chair Kathryn Barger stressed the importance of adhering to evacuation warnings and orders for the community’s safety: “These alerts are issued to protect lives. Conditions can change quickly, and once debris flows begin, it may be too late for emergency crews to reach you.”
The weather service has advised avoiding outdoor activities, driving on roads, and parking near tall trees during the storm while also suggesting preparedness for possible power outages.
As the storm begins to subside, lingering showers are expected to diminish by Wednesday evening, with drying and warming winds predicted to sweep across the county that night.
Southern California’s typical moderate climate should return by Thursday, providing pleasant daytime temperatures in the 70s across L.A. County.
image source from：latimes
