This week’s autumn storm is a first test of LA burn scar flooding risk, and forecasters expect a strong El Niño to keep that risk high through winter. The National Weather Service issued a flood watch for Malibu, Pacific Palisades and Topanga that runs through Thursday afternoon, Oct. 22.
Rain is expected to ease on Friday, with dry, warmer weather over the weekend. The longer concern is the months ahead, because recent fire areas shed mud and debris much more easily than unburned hillsides.
This week’s storm and LA burn scar flooding
The NWS expects 0.5 to 1.5 inches of rain across most of the region from Wednesday through Thursday. South-facing mountains and foothills could see 1.5 to 3 inches. Thunderstorms are possible, and the agency said minor flooding and debris flows are possible especially near recent burn scars.
The City of Los Angeles has crews on standby. In Pacific Palisades, Public Works has installed more than 13,000 feet of K-rail barriers and regularly cleans 18 debris basins. Free sand and sandbags are available at fire stations. As of Oct. 22, no evacuation orders had been reported in the coverage we reviewed. A beach hazards statement also runs through late Thursday night, and a county ocean water quality advisory lasts through at least 3 p.m. Saturday. We covered the coast side in our Tropical Storm Rachel beach hazards report.
Why the winter outlook matters
NOAA’s Climate Prediction Center said on Oct. 8 that El Niño is still strengthening. It put the chance of a strong-to-very-strong event lasting through January to March 2027 above 83%. The next update is due Nov. 12. El Niño winters tend to bring wetter conditions to Southern California, though the center does not forecast any single storm.
Burn areas are more sensitive than most. Soil that has burned absorbs less water, so rain runs off faster and picks up ash and rock. The NWS says burn areas stay at higher risk for at least two years. The state geologist has said that as little as a fifth of an inch of rain in 15 minutes could trigger a debris flow in the Eaton burn scar.
What residents can do now
County officials advise people near hillsides, canyons or burn areas to look up their flood and mudflow risk and make an evacuation plan. Sign up for alerts at the county’s emergency alert page, keep supplies for several days, and clear gutters and drains. Homeowners insurance typically does not cover flood damage, and flood policies can take at least 30 days to take effect, so timing matters. For mud or debris flow concerns, the county Public Works line is 1-800-933-0930.
More local coverage is on our Los Angeles and California hub. Forecasts can change, so check the National Weather Service Los Angeles office for current alerts.