California's Sierra Nevada mountains could see 12 feet of snow through the weekend

By Brad Brooks

(Reuters) - Up to 12 feet (3.66 m) of snow is forecast to fall in California's Sierra Nevada mountains through the weekend, as a one-two punch of dual brutal cold fronts slams into the Pacific Northwest, the National Weather Service said.

Rich Bann, a meteorologist with the NWS, said the western slope of the Sierras will see the heaviest snow, with wind gusts of 100 mph (161 kph) or more likely as the storm crashes over the mountain ridges.

"There could be widespread power outages," Bann said. "This is going to be a really big disruption to life until it tapers off on Sunday."

Blizzard warnings were issued through Sunday for several regions, including the greater Lake Tahoe area, which in the winter is a magnet for ski tourism. The NWS forecast that life-threatening whiteout conditions could persist through the weekend in the area.

The NWS said on Thursday that strong winds had already produced damage around the Lake Tahoe area, and that even stronger winds with gusts up to 80 mph were expected on Friday.

The cold fronts could bring heavy rains at lower elevations in the foothills of the Sierras and across northwestern California, a state that has been soaked by heavy rains this winter. The additional rains on was "increasing the risk of isolated flash flooding," the NWS said.

The storm will also produce heavy snowfall in the Cascade Range mountains in Oregon and Washington, and deeper into the northern Rocky Mountains in Idaho, Montana and Wyoming, the NWS said.

(Reporting by Brad Brooks in Longmont, Colorado; Editing by Jamie Freed)