Cars drive through puddles as heavy rain falls due to an atmospheric river, in an intersection in the Woodland Hills area of Los Angeles, California, U.S., December 24, 2025. REUTERS/Jill Connelly
LOS ANGELES, Dec 24 (Reuters) - Torrential rains drenched Southern California on Wednesday, unleashing widespread flash flooding as authorities urged motorists to stay off roads and residents living downslope of wildfire-scarred foothills and canyons to evacuate.
Downpours measuring an inch (2.54 cm) or more of rain an hour in some areas were spawned by the region's latest atmospheric river storm, a vast airborne current of dense moisture siphoned from the Pacific and swept inland over the greater Los Angeles area.
The Christmas Eve storm was expected to persist into Friday, posing unsafe driving conditions during what would normally be a busy holiday travel period, according to the U.S. National Weather Service.
"Life-threatening" storm conditions were expected to persist through Christmas Day over Southern California, "where widespread flash flooding is underway," the weather service said.
A flash-flood warning was posted across much of Los Angeles County until 6 p.m. PST, urging motorists: "Do not attempt to travel unless you are fleeing an area, subject to flooding or under an evacuation order."
Los Angeles city officials urged residents to heed evacuation orders issued for about 130 homes considered especially vulnerable to mudslides and debris flows in areas where last year's wildfires ravaged the community of Pacific Palisades.
Wednesday's heavy rainfall was accompanied by gusty winds that forecasters said were likely to topple trees and power lines. In upper elevations of the Sierra mountains, the storm was expected to dump heavy snow.
NWS meteorologist Ariel Cohen said 4 to 8 inches of rain had fallen in some foothill areas by 9 a.m. PST, and the Los Angeles City News Service reported numerous rockslides in the mountains. Forecasts called for more than a foot (30.48 cm) of rain falling over some lower-terrain mountain areas by week's end.
Forecasters even issued a rare tornado warning for a small portion of east-central Los Angeles County due to heavy thunderstorm activity over the community of Alhambra.
(Reporting by Steve Gorman in Los Angeles; Editing by Chris Reese)
