SoCal Braces for an Atmospheric River
An atmospheric river slammed into Southern California in the early hours of Tuesday, bringing scattered downpours, powerful winds, and warnings of flooding. The storm also triggered tornado warnings along parts of the Central Coast and prompted evacuation advisories in burn-scarred neighborhoods, including the Palisades, Eaton in Altadena, Hurst in Sylmar, and Sunset in the Hollywood Hills. Officials say burn areas are especially vulnerable to debris flows as the system dumps heavy rain on soil that can’t readily absorb water.
What the Weather Service Is Warning About
As of 8 a.m., rainfall rates near the Palisades burn scar were forecast at 1 to 1.5 inches per hour, prompting a flash flood warning from the National Weather Service (NWS). The Franklin fire burn scar in Malibu also falls under this warning. A severe thunderstorm warning covered parts of west-central Los Angeles County, with a line of storms from Thousand Oaks to Westlake Village capable of hail and 60 mph wind gusts that could damage roofs, siding, and trees.
A broad flash flood watch covers most of the county through Tuesday afternoon, with the heaviest rain predicted Tuesday morning. Meteorologists warn this “rare and very potent storm system” could spark mudslides, more thunderstorms, hail, and gusty winds strong enough to topple trees and power lines. Peak impacts in Los Angeles are expected between 9 and 11 a.m.
On-the-Ground Impacts Across the Region
The storm began in earnest Tuesday morning, delivering rain to Los Angeles and knocking down trees near Balboa Avenue and the 101 Freeway. Roadway flooding has been reported across Los Angeles and Ventura counties, including Hueneme Road in Mar Vista, the 101 near Seward Avenue in Ventura, and I-5 near Sheldon Road in Sun Valley. In some areas, rock and mud covered roads like San Francisquito in Lake Hughes, complicating travel. A downed tree blocked a lane on Burbank Boulevard in Encino.
Experts warn that burned soils don’t soak up water well, increasing the likelihood of debris flows even with moderate rainfall. Officials advise avoiding floodwaters, not driving through flooded roadways, and seeking shelter indoors if outside.
Snow, Winds, and Tornado Warnings Across the Bay Area
Before reaching Southern California, the storm dumped snow in the Sierra Nevada and caused flight disruptions at San Francisco’s airport. In the Bay Area, rainfall totals ranged from about a half-inch to two inches, with flash flood warnings issued for parts of Ventura, northern Santa Barbara, and inland Orange County. Tornado warnings were issued for areas including Pismo Beach, Nipomo, and Oceano as the storm moved through San Luis Obispo County.
Expected Rainfall Totals and Timelines
In Los Angeles County, total anticipated rain ranges from 0.75 to 1.5 inches in coastal and valley zones, and 2 to 4 inches in foothill and mountain regions. The system is also squeezing out temperatures several degrees below normal. Forecasters say peak rainfall rates may drop to 0.33 to 0.66 inches per hour, potentially causing minor road issues and heavy traffic in Tuesday morning commutes. Canyon rockslides are regarded as nearly certain, particularly in flood-prone corridors.
Preparedness and Safety Tips
Authorities have deployed resources in anticipation of debris flows, including sandbags and multiple emergency response teams. Residents are urged to sign up for alerts at NotifyLA.org and heed evacuation orders promptly. Those living in burn scars should have a readiness plan, including an evacuation route and a kit with essentials. People should avoid outdoor activities, stay off roads if possible, and stay away from tall trees or unstable structures during the storm. Power outages are a possibility, so backup lighting and devices are prudent preparations.
Looking Ahead: What Comes Next
Lingering showers are expected to taper by Wednesday evening, followed by drying winds and a gradual return to seasonal, pleasant conditions in the upper 60s to 70s by Thursday. While the worst impacts may pass within a day, officials warn that the storm’s aftereffects—loss of power, road damage, and debris flows—could persist longer in burn areas. Stay informed through local authorities and weather updates as conditions evolve.
