SAN FRANCISCO — The Latest on California storms (all times local):

12:25 p.m.

A rare blizzard warning is in effect in the Sierra Nevada as a powerful winter storm moves through California.

Authorities also warned Thursday of high avalanche danger for the backcountry around Lake Tahoe.

Caltrans reports about 90 miles of Interstate 80 are closed between Colfax, California, and the Nevada state line due to whiteout conditions.

Ski resorts, meanwhile, are benefiting from the storm.

Stephanie Myers, a spokeswoman for Heavenly Mountain Resort and Kirkwood Mountain Resort, estimates snow is falling at about 2 inches an hour.

She says they hope to have a "beautiful bluebird powder day" on Sunday, when the forecast calls for clear conditions.


11:20 a.m.

Authorities in California have issued a mandatory evacuation order for areas of the Santa Barbara County coast in advance of overnight rain and the possibility of debris flows like those that devastated Montecito in January.

Sheriff Bill Brown said the order issued Thursday affects as many as 30,000 people. It includes Montecito, where 21 people were killed by a massive mudslide.

Other areas impacted by the order are Goleta, Santa Barbara, Montecito, Summerland and Carpinteria.

A winter storm moving south through California is expected to reach the Santa Barbara area 100 miles (161 kilometers) west of Los Angeles early Friday.

The evacuation order says residents should be out of the areas by 6 p.m. Thursday. Brown says people won't be forcibly removed if they choose to stay.


6:50 a.m.

A major winter storm is moving across Northern California, bringing heavy snow and strong winds to the Sierra Nevada and steady rain through the region that is disrupting the morning commute.

The California Highway Patrol says dozens of collisions have been reported Thursday morning on San Francisco Bay Area highways and reminds motorists to slow down.

Officials in Southern California recommended people evacuate homes in and around Montecito, where 21 people died in a massive mudslide in January.

In the Sierra, officials warn people to stay off mountain roads.

Forecasters say the cold front will bring snow to the foothill areas of the Sierra as low as 3,500 feet (1,066 meters) before moving south. The U.S. Forest Service has issued an avalanche watch for the Sierra backcountry around Lake Tahoe.


12:00 a.m.

Motorists are warned to stay off Northern California mountain roads as a major winter storm is expected to bring heavy snowfall and powerful winds Thursday.

Meanwhile predictions of widespread showers across the southern end of the state early Friday are raising concern about flash flooding near wildfire burn scars.

Several feet of snow are expected in the Sierra Nevada, where a blizzard warning is in effect. The National Weather Service tweeted simply: "Travel is highly discouraged."

To the south, Santa Barbara County Sheriff Bill Brown said Wednesday that it was too early to tell if the system will bring enough rain to potentially trigger mudslides. He says evacuations are recommended in and around Montecito, where 21 people died in a massive mudslide in January.