Thousands without power as US storms bring rain, snow

Nearly 85,000 households and businesses are without power in the Los Angeles area as storms continue to pummel parts of California, bringing snow to higher elevations and dumping rain and hail in the flatlands.

Interstate 5, the largest highway leading north out of the city, remained closed on Saturday due to heavy snow, while several more southern points of the freeway in and around Los Angeles were closed due to flooding, the California Department of Transportation said.

In Northern California, San Francisco was expected to experience record cold temperatures on Saturday, and the National Weather Service warned residents of the state capital of Sacramento to avoid travel from Sunday through Wednesday as rain and snow started up again after a reprieve on Saturday.

"Extreme impacts from heavy snow and winds will cause extremely dangerous to impossible driving conditions & likely widespread road closures & infrastructure impacts!" the agency said on Twitter.

The next set of storms, expected to hit on Sunday, will bring wind gusts of up to 80 kilometres and hour in the Sacramento Valley, and up to 112km/h in the nearby Sierra Nevada mountains. Yosemite National Park was closed through Wednesday due to severe winter conditions.

A massive low-pressure system driven from the Arctic was responsible for the unusual conditions, said Bryan Jackson, a forecaster at the NWS Weather Prediction Center in College Park, Maryland.

In Southern California, "this is a rare case of a cold, significant storm event," Jackson said.

In a sight that must have delighted many Angelenos on Friday, snowflakes even fell around the Hollywood sign atop Mount Lee in the hills above the city, known for its sunny days and palm trees.

On Saturday, scattered showers and isolated thunderstorms were expected to bring rain, hail and a mixture of snow and moisture called "graupel" to the area, the National Weather Service said.

Even before the latest storm, much of California had experienced an unusually rainy, chilly winter, starting with a spate of deadly "atmospheric river" storms that unleashed widespread flooding, felled trees and triggered mudslides in a state long plagued by drought and wildfires.