Rain flooded Southern California burn scars as a rare tornado risk stretched from Carmel to Los Angeles

Rain falling on Southern California on the afternoon of Wednesday, Oct. 21, 2026, caused flash flooding, especially over wildfire burn scars, according to FOX Weather. The same system carried a low-end tornado risk along a corridor from Carmel south to Los Angeles, an unusual forecast for the central and southern California coast. The two hazards arrived together because a strong Pacific storm was moving ashore over hillsides still stripped of vegetation by recent fires.

Save more, waste less: The Cool Down’s newsletter sends smart, simple changes that help you and the planet in your everyday life.

Subscribe to The Cool Down →

We may earn a commission if you sign up.

Burn scars change how a landscape responds to rain. Healthy slopes soak up and slow water with roots, leaf litter and loose soil, but ground scorched by wildfire can repel water and shed it in a rush, carrying ash, rock and mud into channels and neighborhoods below. Even moderate rainfall rates can produce debris flows on recently burned terrain, which is why forecasters pay close attention to scarred hillsides well before the heaviest rain arrives.

Flash flooding over the burn scars

FOX Weather reported on Oct. 21 that rain in Southern California on Wednesday afternoon caused flash flooding, especially over wildfire burn scars. The report did not name specific locations or give rainfall totals, so the precise neighborhoods affected remain unclear from that account. Its author, Julian Atienza, attributed the forecast to the FOX Forecast Center rather than to a named meteorologist.

The National Weather Service in Los Angeles had flagged the setup ahead of time. Its forecast page, last updated on Oct. 21, called for 0.5 to 1.5 inches of rain generally and 1.5 to 3 inches across south-facing mountains and foothills, and it said minor flooding and debris flows were possible especially near recent burn scars. Peak impacts were expected from late Wednesday morning through late Thursday morning, with isolated to scattered thunderstorms able to bring lightning, heavy downpours, gusty winds, small hail and isolated waterspouts.

The mud and debris flow threat on recently burned ground

AccuWeather’s forecast, written by meteorologist Brandon Buckingham and updated on Oct. 20, spelled out the longer-range worry. It said flash flooding was possible across portions of Central and Southern California, with Los Angeles among the cities in the storm’s path, and that recently burned areas could face mudslides and debris flows as heavy rain fell on scorched ground. The article tied that risk to multiple wildfires that broke out after a stretch of hot, windy weather, including the Norte Fire in Orange County, though it did not name specific burn scars.

The cruel arithmetic is that the same rain helps firefighters while threatening the ground the fires left behind. AccuWeather said midweek conditions should improve firefighting, even as the downpours raised the odds of slides below recently burned slopes. Residents near scars generally depend on local evacuation notices and weather service warnings, since debris flows can start with little lead time once rainfall rates climb.

AccuWeather laid out the timing in some detail. Rain and some mountain snow were due to begin in California on Tuesday night, Oct. 20, with the storm’s core reaching the state on Wednesday and bringing pockets of heavy rain and thunderstorms, before the system slowed and pushed on through the Southwest and Rockies later in the week. Tropical moisture from the eastern Pacific streaming north ahead of the storm was part of the fuel, and the company said waterspouts and locally gusty winds were possible along the coast, a combination that rarely appears in the same California forecast.

The storm also carried a longer-term angle for a region that depends on cool-season rain. AccuWeather noted that several fall storms this season had carried tropical moisture into the Southwest, causing flash flooding while slowly easing drought, and said continued stormy weather would be needed this fall and winter to refill major western reservoirs. It added that El Niño historically favors above-average winter precipitation in Central and Southern California, which would be welcome for water supplies and a mixed blessing for slopes already burned bare.

A low-end tornado risk from Carmel to Los Angeles

Tornadoes are rare enough on the California coast that even a low-end risk drew notice. FOX Weather’s forecasters outlined a low-end tornado risk along a corridor from Carmel south to Los Angeles, which stretches roughly the length of the central and southern coast. A low-end designation means the ingredients were present but the probability at any one location stayed small. The weather service in Los Angeles separately listed isolated waterspouts among the possible thunderstorm hazards.

Weather.com described the broader picture on Oct. 21, with moisture, flash flooding and mountain snow all in play from California across Arizona and New Mexico. Farther east, azfamily.com reported that tornado warnings in the Flagstaff area on Oct. 21 rested on radar-indicated rotation, a reminder that the same storm system was producing rotating storms hundreds of miles from the California coast.

FOX Weather said more storms could develop on Thursday, Oct. 22, as the system moved east toward the Rockies, which would carry the heaviest threat away from California. Burn-scar slopes can stay unstable for some time after rain ends, so the ground may remain vulnerable to later storms even after the sky clears.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

Save more, waste less: Subscribe to The Cool Down →

We may earn a commission if you sign up.