'Powerhouse' Winter Storm Prompts Warnings In 7 States; Avalanches Possible, Officials Say

A "powerhouse winter storm" is expected to hit the Western United States within the next few days, bringing widespread heavy mountain snow, gusty winds and heavy rains locally, the National Weather Service (NWS). Winter Storm Warnings have been issued in seven states.

"At the peak, very heavy snow rates in excess of 3 inches per hour are forecast," the NWS Weather Prediction Center (WPC) said Wednesday.

Between 16 to 24 inches of snow is expected in some parts of California, Idaho, Wyoming and Montana, the office noted, adding that "backcountry avalanches" are possible.

Backcountry areas are mountainous ranges where avalanche management is reduced due to location.

Some areas in the said states may experience between 24 to 30 inches of snow from Thursday evening through Friday.

In California, officials at the NWS in Sacramento warned against mountain travel from Thursday evening through Friday and during the weekend due to heavy mountain snow.

The NWS in Medford, Oregon said travel is "highly discouraged" from Wednesday night through Sunday" in southwest Oregon due to the weather conditions.

The NWS in Las Vegas similarly discouraged residents from hiking or camping, while the NWS in Boise warned against winter driving.

In Wyoming, the NWS in Riverton said significant snow is expected in the western part of the state Thursday through Friday.

Winter Storm Warnings in Oregon effective through 4 p.m. Thursday:

• Northern Blue Mountains
• East Slopes of the Oregon Cascades

Winter Storm Warnings in Washington effective through 4 p.m. Thursday:

• Northwest Blue Mountains
• Northeast Blue Mountains – Peola, Mountain Road, Anatone and Cloverland Road

Winter Storm Warning in Idaho effective through 7 p.m. Thursday:

• Idaho Palouse – Moscow, Potlatch, Plummer and Genesee

Winter Storm Warnings in Idaho effective through 5 a.m. Friday:

• Sun Valley Region – Big Lost Highlands, Copper Basin, Frank Church Wilderness, Sawtooth, Stanley Basin and Wood River Foothills
• Boise Mountains – West Central mountains zone
• Northern and Southern Clearwater Mountains – Elk River, Highway 11 Pierce to Headquarters, Pierce, Dixie, Elk City and Highway 12 Lowell to Lolo Pass
• Central Panhandle Mountains – Dobson Pass, Wallace, Lookout Pass, Mullan, Fourth of July Pass, Pinehurst, St. Maries, Osburn, Kellog and Fernwood

Winter Storm Warning in Idaho effective through 11 a.m. Friday:

• Lost River Range – Beaverhead, Lemhi Highlands

Winter Storm Warnings in Idaho effective through 5 p.m. Friday:

• Island Park – Ashton Hill, Raynolds Pass, Targhee Pass and Kilgore
• Caribou Range – Bear River Range, Big Hole Mountains, Teton Valley, Emigration Summit, Driggs, Victor, Ashton, Tetonia, Swan Valley, Pine Creek Pass and Wayan

Winter Storm Warnings in California effective through 4 a.m. Friday:

• Grant Grove Area - Kaiser to Rodgers Ridge, Kings Canyon NP, Sequoia NP, Upper San Joaquin River and Yosemite NP outside of the valley
• Lassen-Eastern Plumas-Eastern Sierra Counties
• Greater Lake Tahoe Area

Winter Storm Warnings in California effective through 10 a.m. Friday:

• Trinity – Northern and Southern Trinity
• Humboldt – Northern and Southern Humboldt Interior
• Mono County
• Eastern Sierra Slopes – Whitney Portal and Aspendell

Winter Storm Warnings in Montana effective through 11 a.m. Friday:

• Continental Divide (along the Rocky Mountain Front) – East Glacier Park Region and Southern Rocky Mountain Front
• Little Belt – Highwood Mountains
• West Glacier Region – Bad Rock Canyon, Essex, Polebridge, Marias Pass and Highway 83 Bigfork to Swan Lake
• Low Clark Fork Region – Evaro Hill, Highway 200 Thompson Falls to Plains, Highway 200 Trout Creek to Heron and I-90 Lookout Pass to Haugan

Winter Storm Warnings in Montana effective through 5 p.m. Friday:

• Gallatin County – Madison County Mountains and Centennial Mountains
• Beartooth Mountains
• Crazy Mountains

Winter Storm Warnings in Wyoming effective through noon Friday:

• Yellowstone National Park
• Absaroka Mountains
• Teton Mountains – Gros Ventre Mountains
• Jackson Hole
• Wind River Mountains West
• Star Valley
• Salt River – Wyoming Ranges

Winter Storm Warning in Nevada effective through 4 a.m. Friday:

• Greater Lake Tahoe