Early season storm sends a deluge of rain to California

LOS ANGELES – An early season storm lashed northern California with drenching rain on Oct 13 and was moving through the evening towards southern California, where officials in Los Angeles county issued evacuation warnings in some areas.

Thunderstorms could unleash heavy rain that sends torrents of water, mud, sand, rocks, trees and boulders down steep slopes in places recently burned by wildfires, forecasters warned.

The National Weather Service’s office in Oxnard, California, said that debris flows were possible in burn scars across San Luis Obispo, Santa Barbara, Ventura and Los Angeles counties; areas burned by the Palisades and Eaton fires in January and by the Bridge fire in 2024 were particularly at risk.

Evacuation warnings mean that hazardous conditions are possible and that people should keep an eye out for evacuation orders calling for immediate action.

Ms Lisa Phillips, a meteorologist with the weather service’s Oxnard office, said that it was unlikely that widespread debris flows would occur in all of the burn scars, but that it was likely that at least one area would get hit with a heavy downpour that creates problems.

“We’re confident that something will happen somewhere, but where that happens, that’s where the confidence is lower,” she said.

The weather service called the large storm system that is bringing a chance of rain up and down the state “rare for October”. Rainfall totals across California with this multi-day storm could range from less than 1cm to 7.5cm of rain.

Rain started in south-west Oregon and far northern California early on the morning of Oct 13 and continued through the day. As at about 5pm local time on Oct 13, downtown San Francisco had recorded 1.7cm of rain. Northern California will dry out through the day on Oct 14.

Mr Rich Otto, a meteorologist with the Weather Prediction Centre, said the storm was pulling in moisture from the Pacific Ocean and funnelling it into California.

“It’s not the highest degree of moisture, but it’s still atypical compared to the average for this time of year,” he said. “There’s potential for locally high rainfall rates.”

Snow was falling in the Sierra Nevada on Oct 13 and will most likely continue into Oct 14 and early Oct 15.

“This storm is expected to bring the first measurable snow of the season,” said Ms Kate Forrest, a meteorologist with the weather service in Sacramento.

A winter weather advisory was issued through Oct 15 for the Lake Tahoe Basin, where the highest peaks were predicted to pick up 61cm of snow. The heaviest snow in the Sierra would most likely fall on Oct 13 into the following day.

As at 5pm on Oct 13, the rain had yet to reach Los Angeles county, but Ms Phillips said the rains to the north were quickly moving south.

“It’s raining in San Luis Obispo county right now,” she said. “We’re expecting it to start pushing farther south into the region tonight and into tomorrow morning.”

The chances for rain will continue into Oct 14 across central and southern California. NYTIMES