Ponding water shut down multiple lanes of U.S. 101 in downtown Los Angeles before dawn, and there were numerous reports of cars being disable by freeway potholes.
Working inside a nearly 18-foot-deep snow pit at the UC Berkeley Central Sierra Snow Lab, from left, Shaun Joseph, Claudia Norman, Helena Middleton take measurements of snow temperatures ahead of a weather storm on March 9, 2023, in Soda Springs, California. (Karl Mondon/Bay Area News Group via AP)
The National Weather Service said the storm is a Pacific low pressure system interacting with California's 12th atmospheric river since late December.
California's unexpected siege of wet weather after years of drought also included February blizzards powered by arctic air.
The storms have unleashed flooding and loaded mountains with so much snow that roofs have been crushed and crews have struggled to keep highways clear of avalanches.