Southern California has been hit by one of the most intense winter storms in recent memory during the Christmas holiday, as a series of powerful atmospheric rivers — including the so-called “Pineapple Express” — drenched the region with torrential rain, triggered widespread flooding and prompted emergency warnings.
The storms, which began late Tuesday and intensified on Christmas Eve, brought moisture-laden air from the tropical Pacific, resulting in rainfall far above normal for this time of year. Many parts of Southern California typically receive only a fraction of an inch of rain in late December, but officials reported several inches — and in some mountain communities up to 10 inches — falling in just a short period.
As the deluge continued, flash flood warnings were issued across Los Angeles and most of Southern California, with the National Weather Service describing conditions as “life-threatening” and warning that heavy mountain snow and high winds would also accompany the system.
In response to the hazardous conditions, California Governor Gavin Newsom declared a state of emergency in multiple counties, including Los Angeles, to allow rapid deployment of resources and support for affected communities. Emergency responders dealt with flooded streets, fallen trees and widespread power outages that left tens of thousands of homes and businesses without electricity.
Some areas already bore the brunt of the intense rainfall, which softened soil and heightened the risk of dangerous mudslides, particularly in regions scarred by earlier wildfires such as Pacific Palisades and Malibu. Evacuation warnings were issued for vulnerable neighbourhoods, and local authorities urged residents to avoid travel and seek shelter.
The storm’s impacts extended beyond rain. Mountain passes saw heavy snowfall and white-out conditions, complicating holiday travel and raising concerns about avalanches in the Sierra Nevada.
Forecasters warned that the wet weather could linger through Christmas Day as another system approached, making this potentially one of the wettest Christmas periods in years for Southern California.
Local officials and meteorologists stressed the need for caution as residents dealt with travel disruptions, emergency operations and the ongoing risk of floods and landslides.