Los Angeles, California – A strong atmospheric river is expected to bring heavy rain and a high risk of flash flooding to Los Angeles through Friday, prompting warnings for urban flooding and debris flows.
According to the National Weather Service and the Weather Prediction Center, portions of Los Angeles County are under a high risk of excessive rainfall capable of producing rapid flash flooding. Forecast models show the most intense rainfall rates developing as the moisture plume stalls over Southern California midweek.
The highest concern is across the Los Angeles Basin, coastal areas, and the southern slopes of the Transverse Ranges, including the San Gabriel and Santa Monica Mountains. Forecasters warn that saturated ground conditions could lead to mudslides, rockfalls, and debris flows, particularly near burn scars and steep terrain.
Urban flooding is also possible in downtown Los Angeles, Hollywood, Long Beach, and surrounding communities, where heavy rain could overwhelm drainage systems. Roadway flooding and reduced visibility may impact travel during peak commute hours.
In addition to rainfall, strong winds are expected across the region, especially in higher elevations, raising the risk of downed trees and localized power outages. While snow levels will remain high in Southern California, significant snowfall is expected farther north in the Sierra Nevada.
Residents are urged to avoid flooded roadways, monitor local alerts, and prepare for rapidly changing conditions as the storm system persists through the end of the week.
