SACRAMENTO, United States - A key freeway remained shut down and thousands of households were without power in California on Sunday, as a strong blizzard continued to slam the US state with heavy snow and howling winds.

The winter storm has gripped Northern California and the mountain ridges since Thursday, pummeling the region with heavy snowfall reaching a staggering 3.6 meters and howling winds exceeding 3.5 kph.

The worst blizzard of the winter has severely disrupted transportation network with more than 160 km of Interstate 80, the main route connecting Reno, Nevada, to Sacramento, California, remaining closed near the Nevada border on Sunday.

There was "no estimated time of reopening the freeway", the California Highway Patrol (CHP) warned. Hundreds of travelers were trapped in their vehicles for hours, and more than 300 vehicles were stranded.

Power outages have also become a major concern. Over 12,000 homes and businesses in California were still without power as of Sunday evening, according to tracking website PowerOutage.us.

The relentless snowfall has hampered efforts to clear highways of snow, with crews struggling to operate equipment amid the harsh conditions.

California Department of Transportation, which maintains the state's highway system, shared a video on social media on Sunday, showing snow blowers sluggishly navigating through heavy snow with limited visibility.

The agency reported significant equipment failures, with only a fraction of their usual snow removal capabilities operational. "We have been down to two of 10 blowers at our central hub in Kingvale and six out of 20 from Auburn to the Nevada state line," it said in a post on X.

The highest elevations in the mountains are bearing the brunt of the storm's fury. White-out conditions and hurricane-force winds have created a treacherous landscape.

Blizzard warnings remain in effect for the Sierra Nevada, a mountain range between the Central Valley of California and the Great Basin in the Western United States, with forecasts predicting another 0.6-1.2 meter of snow for areas above altitude 1,200 meters on Monday and Tuesday, and 2.6-10 centimeters of snow for areas in the upper foothills on Sunday, according to the National Weather Service in Sacramento.

The National Weather Service "highly discourages" any mountain travel due to the "extremely difficult to impossible" conditions.

Brutal white-out conditions and near-zero visibility pose a severe threat to motorists, potentially leading to lengthy delays, road closures, and power outages.

Numerous ski resorts and chairlifts remain closed, unable to operate safely under extreme conditions. The weather service's data revealed the staggering 72-hour snowfall totals: Sugar Bowl ski resort got the largest volume of snow at 2.2 meters, followed closely by Soda Springs at 2.1 meters and Kingsvale at 1.9 meters.

National Weather Service meteorologist William Churchill issued a stark warning, labeling the storm a "life-threatening concern" for residents near Lake Tahoe and classifying it as an "extreme blizzard."

The blizzard's reach extended beyond California, with winter weather alerts affecting approximately 6.5 million people across the Mountain West. Areas of Nevada, Utah, and Colorado also felt the storm's effects.

A rare event, facilitated by the storm's moisture, brought an additional element of surprise: two tornadoes touched down in Central California over the weekend.

One tornado struck Madera County on Friday, while the other hit Kings County on Saturday. The Friday tornado left an elementary school damaged, according to the weather service office in Hanford.