Significant winter storm to bring heavy snow, rain, and strong winds to Southern California through Thursday, 3/13/25

A powerful winter storm is set to impact Southern California from Tuesday night through Thursday, bringing heavy snow, significant rain, and strong winds. Flood watches and hazardous travel conditions are expected.

by Mac Douglass

Updated March 13, 2025

Southern California Winter Storm Warning Issued. — A winter storm is expected to bring heavy snow, rain, and strong winds to Southern California, with hazardous travel conditions likely.

A powerful winter storm is set to impact Southern California from Tuesday night through Thursday, bringing heavy snowfall to the mountains, significant rainfall across the region, and gusty winds that could create hazardous travel conditions.

Here are latest details on the upcoming storm, including what you can do to prepare for it. #cawx #larain pic.twitter.com/W9vACttt8V
— NWS Los Angeles (@NWSLosAngeles) March 11, 2025

Mountain Snowfall and High Winds

According to the National Weather Service (NWS) in Los Angeles/Oxnard, snow accumulations of 1 to 2 feet are expected at elevations above 6,500 feet, with up to 12 inches of snow likely above 5,500 feet. Snow levels will drop as low as 3,000 feet by Thursday, potentially affecting major mountain passes.

A significant winter storm is set to impact Southern California, bringing heavy snowfall, strong winds, and dangerous driving conditions in mountain areas. The National Weather Service warns of possible road closures and advises travelers to carry chains and emergency supplies

Winds from the south-southwest are forecasted to gust between 40 and 60 mph, creating dangerous whiteout conditions in higher elevations. The NWS warns of possible road closures in affected areas, particularly along Interstate 5 near the Grapevine and sections of Highway 14 from Acton to Palmdale and Highway 33 north of Ojai.

Widespread Rain and Flooding Concerns

In addition to mountain snow, this storm will bring widespread rain to coastal and valley areas. Rainfall estimates range from 1.0 to 2.0 inches for lower elevations and 2.0 to 4.0 inches in foothill and mountain areas.

Southern California is under a Flood Watch as a winter storm moves in, with widespread rain expected to cause roadway flooding, mudslides, and debris flows. The heaviest rain is forecasted late Wednesday into Thursday.

Peak rainfall rates could reach 0.50 to 0.75 inches per hour, with a 10-20% chance of intense downpours exceeding 1.0 inch per hour, primarily late Wednesday into early Thursday. Forecasters are also monitoring the risk of thunderstorms, which could bring brief but heavy rainfall.

A Flood Watch is in effect from 6 p.m. Wednesday through 6 p.m. Thursday for portions of Southern California, including Los Angeles, Ventura, and Santa Barbara counties. The main threats include roadway flooding, minor rock and mudslides, and shallow debris flows near recent burn scars. There is a 30-50% chance of significant debris flows in areas most susceptible to heavy rainfall.

Travel and Safety Advisories

The National Weather Service is urging residents to prepare for hazardous travel conditions, especially in mountain passes where snow and strong winds will reduce visibility. Travelers are advised to carry chains and winter driving supplies and to avoid unnecessary travel if possible.

For those in lower elevations, localized flooding and road closures could create delays and disruptions. Residents in flood-prone areas should stay alert for potential evacuation orders if conditions worsen.

This developing storm will continue to be monitored, and residents are encouraged to stay updated through official sources such as the National Weather Service.