Snow storm headed for the Sierra mountains; travel nearly impossible

TAHOE, Calif. - Enjoy Friday's mostly sunny weather while it lasts. That's because a winter storm is moving in on Saturday morning with rain expected in the Bay Area and mountain snow predicted to blanket the Sierra Nevada.

Blizzard-like conditions are possible along Interstate Highway 80 by late Saturday morning and will last through the evening, according to the National Weather Service.

KTVU meterologist Steve Paulson said if you're going to go skiing, do it on Friday because traveling on Saturday will be treacherous. 

Caltrans reiterated on social media that travel in the mountains may be "difficult to impossible" and urged people to change their plans. 

The NWS said the worst conditions for driving will be between 10 a.m. and 10 p.m. Saturday, with possible lingering impacts on Sunday. Gusty winds up to 50 mph, combined with the snowfall rates of 3 inches per hour, will likely lead to whiteout conditions. 

The NWS also issued a winter storm watch for the Siskiyou Mountains and Sierra Nevada from Saturday morning through Sunday morning. At Lake Tahoe, a half-foot to a foot of snow is expected, while higher elevations, including Donner Summit, should accumulate 1 to 2 feet.

Snowfall totals are expected to range from 1 to 2 feet above 7,000 feet and up to a foot at Lake Tahoe. Mammoth Mountain and Tioga Pass are forecast to receive between 8 inches to a foot, while Yosemite Valley is likely to exceed a foot of fresh powder.

The system should be gone by late Sunday morning but two more storms are expected next week, on Wednesday and Friday.