Death toll rises to 14 from California winter storms as Biden declares emergency

US President Joe Biden declared a federal state of emergency Friday in the state of California as back-to-back winter storms have already left at least 14 people dead.

At least one death occurred during the current severe weather system. The unidentified individual was killed when a roof collapsed at a coffee warehouse in Oakland, the Los Angeles Times reported, citing authorities.

"There's a risk of flooding, rock and mudslides and heavy snowfall, increasing the likelihood of road closures and avalanches," the California Department of Transportation tweeted.

Emergency officials issued evacuation warnings Friday to areas expected to be hit hardest by the next bout of severe winter weather.

While forecasters expect the mountainous regions to be hit by several feet of snow, lower-lying areas also expect floods from heavy rains and runoff from the melting snow.

More than 39 million residents are under warnings or advisories, according to the National Weather Service (NWS), with millions across the state under at least 90 flood watches and advisories.

"A winter storm will produce copious amounts of heavy snow to the high terrain of northern and central CA and significant rainfall and flood threats across much of CA," the Transportation Department tweeted.

Central California is expected to be hit the hardest with dozens of counties across the state already under a state of emergency.

"This is an unrivaled, unparalleled weather event not experienced in several decades, perhaps back to 1969," said NWS science and operations officer Kris Mattarochia at a news conference.

California has been battered by an unusual string of severe winter storms in recent weeks with the latest back-to-back storms wreaking chaos.

Thousands of emergency crews have been working day and night conducting search and rescue efforts and trying to dig residents out of the snow that has buried homes and trapped them.

Gov. Gavin Newsom expanded last week's state of emergency from 13 counties in the central part of the state to now include 21 additional jurisdictions. A total of 34 counties are currently under a state of emergency.

"CA is working around the clock with local partners to deploy life-saving equipment and first responders to communities." the governor's office tweeted. "More storms are coming - stay safe."