LOS ANGELES -- The latest bout of harsh, wintry weather to lash California drifted into neighboring states of the Desert Southwest on Wednesday as authorities reported at least five storm-related deaths in and around San Francisco, all from fallen trees.

As California's onslaught of rain, wind and mountain snow subsided, downed power lines from Tuesday's storm left more than 92,000 homes and businesses without electricity as of Wednesday afternoon, while lingering floods kept 14,000 people under evacuation orders.

Nearly 48,000 others statewide were warned to be ready to flee to higher ground in the event rain-swollen streams overflow their banks or storm-weakened levees fail, according to Diana Crofts-Pelayo, a spokesperson for the California Office of Emergency Services.

The bulk of mandatory evacuation orders, covering some 12,000 people, were in Tulare County, a flood-stricken region in the San Joaquin Valley, where high water from recent levee failures has inundated a number of communities.

The storm was the product of yet another in a recent succession of "atmospheric rivers", immense airborne currents of dense water vapor carried aloft from the ocean and flowing overland in bouts of heavy rain and snow.

It marked the twelfth such storm to sweep the West Coast since late December, the latest one notable for extreme winds that accompanied the precipitation and in some places wreaked the most havoc.

Five people were killed by trees toppled by high winds across California's Bay area on Tuesday - two in San Francisco, one in Oakland and one each in Contra Costa County and San Mateo County, according to officials and local media reports.

At least two of the victims died in their vehicles, and one was crushed inside a tent.