Powerful Pacific Storm Drenches Southern California, Triggering Flash Floods, Mudslides and Widespread Evacuations

A Surge of Pacific Moisture Hits the Coast

A long plume of tropical moisture sweeping in from the Pacific Ocean pushed into California this week, building into a powerful storm system that reached Southern California by Friday. The atmospheric river soaked the San Francisco Bay Area first, then moved south, unleashing heavy rain, strong winds and rapid flooding from Santa Barbara County to Los Angeles, CA.

By early Saturday, the National Weather Service in Los Angeles and Oxnard reported rainfall rates near one inch per hour in coastal zones. Skies dimmed over Los Angeles, CA, as dark cloud bands dragged inland. Hillsides glistened with saturated soil, and runoff surged toward the coast.

More than four inches of rain had already fallen across parts of Santa Barbara County on Friday. In some communities, mudslides began before dawn, spreading debris over roads still slick from earlier storms.

Flash Flooding and Mudslide Threat Across Burn Scars

The saturation of vulnerable slopes quickly turned into a dangerous situation. Much of the region’s emergency response focused on neighborhoods scarred by recent wildfires. Burn scars from the Palisades Fire, Eaton Fire and Hurst Fire created unstable soil that could not absorb the rainfall.

Los Angeles Mayor Karen Bass warned residents in a Saturday morning statement.
“Due to the potential for debris flows, an Evacuation Warning remains in effect within and around all recent burn scar areas," she said. Specific high-risk properties remained under mandatory evacuation orders through Sunday morning.

Law enforcement teams moved door to door in steep hillside communities, urging people to leave before conditions deteriorated. With the storm strengthening, the risk of sudden mudslides grew by the hour.

Meteorologists projected 2 to 4 inches of rain across the greater Los Angeles area through Sunday, with some neighborhoods expected to approach 6 inches. South- and west-facing slopes along the coast were forecast to receive 6 to 10 inches, far exceeding typical November rainfall.

Second Wave of Heavy Rain Deepens the Hazard

AccuWeather meteorologists warned that the storm would intensify through Saturday evening. Rainfall that had already overwhelmed drainage systems continued to fall on ground unable to absorb more water.

Communities from Ventura County to the City of Los Angeles remained under flood warnings. Reports increased of washed-out rural roads, blocked canyon routes and waterlogged intersections. In Santa Barbara County, new mudslides forced closures in several communities.


Much of the Los Angeles basin sat under a Level 3 of 4 flooding risk, according to the Weather Prediction Center. Rainfall totals exceeded two inches early Saturday in Ventura County. Los Angeles and Long Beach recorded more rain in one day than is typical for the entire month of November.

In Oxnard, 1.56 inches fell by mid-day, more than double the city’s November average of 0.71 inches.
Los Angeles had recorded 2.75 inches since early Friday, surpassing three Novembers’ worth of rain in less than two days.

Residents described brief breaks between downpours, followed by intense new bursts.
“The street looked like a moving river," a Malibu, CA, resident said.
“You could see the hillside sliding in thin sheets."

Burn Scars on Alert

Wildfires leave behind unstable terrain that becomes highly reactive during intense rainfall. Extreme heat can fuse soil layers into a water-repellent crust. When heavy rain falls on that surface, water races downhill in sheets, carrying rock, ash and debris.

The National Weather Service in Los Angeles issued multiple warnings for the Palisades, Hurst, Sunset, Eaton and Bridge burn scars, cautioning that conditions were favorable for “significant debris flows."

Aerial footage showed runoff channels churning with brown water and debris. Storm drains clogged with branches and mud. Crews monitored evacuation routes as runoff surged.

Storm Outlook and Additional Systems Ahead

The heaviest rainfall was expected to ease late Saturday, but saturated ground will not dry quickly. Showers will linger into Sunday, and even modest rainfall could trigger new flooding, especially in areas prone to slow drainage.

A second Pacific storm is projected to move south along the California coast from Sunday night into Monday. While expected to be less intense, it may still deliver one to two inches of rain in coastal areas and additional snow in the Sierra Nevada.

Forecasters noted that the weekend storm could briefly lower wildfire risk and improve water storage conditions in parts of the Colorado River basin. Reservoirs across California remain at or above mid-November averages.

But for now, communities from San Francisco, CA, to Los Angeles, CA, continue to face the immediate hazard of saturated hillsides, flash flooding and persistent rainfall falling on ground that can no longer absorb it.