Blizzard Conditions Could Bury California Mountain Towns In Feet Of Snow

Residents, businesses, and visitors are urged to prepare for a powerful winter storm that will lead to lengthy travel disruptions and power outages in California’s Sierra Nevada. 

AccuWeather meteorologists say the combination of heavy snowfall rates of 2-4 inches per hour, combined with 40-60 mph wind gusts, will lead to blizzard conditions and a life-threatening situation for people caught unprepared in the storm.

A blizzard is defined as a storm with falling or blowing snow, winds in excess of 35 mph, and visibility less than, or equal to, one-quarter of a mile for three consecutive hours of more.

Snow is expected to pick up across portions of Oregon, northern California, and northwestern Nevada by Wednesday night. AccuWeather meteorologists say heavy snow will expand through the northern and central Sierra on Thursday. The best chance for snow totals of 4-8 feet or more will be at elevations above 5,000 feet in the Sierra Nevada and Klamath Mountains.

“As the heaviest precipitation moves through Northern and Central California, snow levels will drop over northern regions in particular. They could dip as low as 2,000 feet in the Siskiyou Mountains during the worst of the storm,” said AccuWeather Senior Meteorologist Heather Zehr. The worst conditions are expected Friday night.

Preparations for the winter storm in Northern California should be completed before Wednesday night. People that live and work in upslope or mountainous regions should gather emergency supplies, food, and bottled water.

Generators should also be checked, fueled and set up in a safe location with proper ventilation to prepare for power outages.

“In addition to the mountains, locations across the inner valleys and coasts can face windy conditions which could raise concern for power outages, given the saturated ground,” said AccuWeather Meteorologist Joseph Bauer.

Blowing snow, rapid accumulation, and low visibility will likely lead to delays and extended closures on some highways and mountain passes across the northern and central Sierra region later this week.

“With heavy snowfall rates, it will be difficult for road crews to keep up, and even major roads are likely to be severely impacted,” said Zehr.

Major travel and commerce links including Interstate 80 at Donner Pass could be buried by 6-10 feet of snow.

An estimated average of 30,000 passenger vehicles and 6,200 semi-trucks use I-80 at Donner Pass daily, according to the California Department of Transportation.

Rail traffic and commerce in the area may also be severely impacted by the heavy snow.

“This will be a colder storm than previous ones. It doesn’t have the big atmospheric river that’s usually a warm air mass associated with it,” explained AccuWeather California Expert Ken Clark. “We do expect all that wind energy coming off the Pacific to ram up against the Sierra Mountains and create tons of snow.”

The combination of rich moisture and winds out of the southwest will set the stage for the largest snowfall totals the Sierra has seen so far this winter.

“This storm is rolling right out of the Gulf of Alaska, which is pumping down cold Arctic air into the region, leading to lower snow levels than we’ve seen in recent storms,” said Bauer.

“After a very slow start to the snow season in the Sierra, this storm will not only push snow totals above the historical average so far, but likely bring totals to the seasonal averages, with two months left in the snow season,” said AccuWeather Chief Broadcast Meteorologist Bernie Rayno. “Extreme conditions will occur in mountain ranges such as the Sierra and Siskiyous, resulting in road and pass closures.”

California’s snow/water equivalent levels statewide are currently at 82 percent of historical average.

“From this storm alone, we’re going to really pump up that snowpack across the Sierra. That’s good news for the reservoirs come this summer,” said Clark.

Said AccuWeather Chief Meteorogist Jonathon Porter, “This storm is sure to slow  the movement of both people and goods through this region. With the significant amount of snow expected, people should prepare now for these challenges and check the AccuWeather forecast often to stay ahead of the storm.”