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Multi-day storm is threatening flooding and mudslides in Southern California: What to expect and when

By CNN

Published November 14, 2025 7:16 am

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By CNN Meteorologists Briana Waxman, Taylor Ward

(CNN) — A strong Pacific storm is bringing soaking rain to Southern California and raising the risk of life-threatening flooding, mudslides and debris flows, especially near burn scars in the Los Angeles area.

A mix of heavy rain and strong winds moved through northern and central California on Thursday. Widespread rainfall totals of 1 to 2 inches were observed along the coast into Friday morning, with isolated amounts of 3 to 5 inches in the coastal mountain ranges.

San Francisco received nearly an inch and a half of rain Thursday, almost 75% of November’s average. November marks a transition into the rainier winter season, with December to February marking the wettest months of the year in the Bay Area.

Winds in the higher elevations gusted 60 to 80 mph Thursday with San Francisco gusts topping 50 mph.

The winds started to ease as the system dropped into Southern California early Friday, but the flood threat is intensifying as an atmospheric river feeds moisture from the ocean into the storm.

Parts of the region – including much of the Los Angeles area – are under a Level 3 of 4 risk of flooding rainfall on both Friday and Saturday, according to the Weather Prediction Center.

An initial wave of heavy rain for southern California caused flooding and a mudslide late Thursday night on portions of Highway 101 in southern Santa Barbara County, according to the National Weather Service. This round of rain is expected to ease by Friday afternoon.

A second, more intense wave will move into the region Friday night into Saturday, with prolonged heavy rain possible. Rainfall rates could be as high as an inch per hour at times.

This second round of rain will also have the added danger of falling over already-wet ground, which struggles to absorb additional rain and will start flooding quicker than dry ground.

There’s also the potential for isolated severe thunderstorms embedded within the heavier rain Friday night into Saturday. Some of these storms could produce damaging wind gusts, hail and perhaps a short-lived tornado.

Much of the Los Angeles area is under a flood watch through 10 p.m. Saturday. The National Weather Service warns that the storm could trigger life-threatening debris flows, knock out power and flood roads.

Burn scar areas on alert

Burn scar areas from recent wildfires in the region will be particularly vulnerable to mudslides and debris flows. Not only do wildfires destroy vegetation that would normally soak up some of the rainfall, but their extreme heat can alter the soil, creating a water-repellent layer just below the surface.

Officials have warned residents near the recent Palisades, Hurst and Sunset fires’ burn scars to be prepared to evacuate.

“Residents, especially those in vulnerable areas, should start taking precautions immediately to prepare for the storm and protect their interests,” the National Weather Service in Los Angeles said. “This scenario would potentially create many significant impacts area-wide, including possible debris flows in the burn areas, significant ponding of roads and highways, mudslides through the canyons, fallen trees, etc.”

Residents can pick up sandbags at Fire Stations throughout the City, with sand also available for free at select locations.

The heaviest rain should ease late Saturday, but the region isn’t in the clear right away. Showers linger into Sunday, and the ground will be saturated. It won’t take much rain to trigger more minor flooding or keep roads slick, especially in spots that usually drain slowly after big storms.

CNN Meteorologist Mary Gilbert contributed to this report.