Snowstorm shuts down Little Cottonwood Canyon, leaves thousands without power

Avalanche danger is high across much of the state, Utah Avalanche Center says.

(Trent Nelson | The Salt Lake Tribune) Circle Awl Snow Avalanche Area in Big Cottonwood Canyon on Thursday, Dec. 29, 2022.

A New Year’s Day snowstorm brought heavy snow to Utah’s mountains Sunday, as well as caused power outages in the Salt Lake Valley.

Over 48 hours, Brighton received 29 inches of snow, Sundance received 42 inches (3 1/2 feet), Solitude got 27 inches, Deer Valley got 24 inches, and Alta got 23 inches, according to Ski Utah.

The Utah Department of Transportation announced that Little Cottonwood Canyon would be closed all day Sunday while road and avalanche crews work. As of Sunday afternoon, there was no estimated opening time.

John Gleason, the spokesperson for UDOT, told The Salt Lake Tribune that avalanche mitigation in Little Cottonwood was “going great” as crews dealt with “thick and heavy” snow.

“It’s a great thing because we need all that snow, but it’s also caused us to close down the canyon to do this avalanche control work,” Gleason said. “We put safety first and we won’t open the canyon until we’re sure it’s a safe situation.”

Big Cottonwood Canyon remained open, but UDOT tweeted that travelers should “be prepared for all road conditions” Sunday and expect delays in the evening. UDOT advised people to make sure they have proper traction on their vehicles, remember winter driving skills, and have a full tank of gas.

Thousands of people in Salt Lake County were left without power Sunday afternoon, according to an outage map from Rocky Mountain Power.

“Heavy wet snow is impacting the Salt Lake Valley through this evening causing a high number of outages,” the utility said. “It will take some time to assess damage, make repairs and restore power because of the extent of the damage. Some customers may experience multiple outages or extended outages.”

Rocky Mountain Power reminded people to be careful with heat sources, use portable generators outdoors away from windows and doors, and check on vulnerable neighbors.

Little Cottonwood’s backcountry is closed through Monday at 8 a.m., but Gleason urged people to avoid all backcountry areas at the moment as “conditions are just not safe.”

Avalanche danger is high across much of the state, according to the Utah Avalanche Center.

The town of Alta has been under an “interlodge” order since 11 p.m. Saturday. The order means that residents cannot leave the building that they’re currently in due to avalanche danger. Further details about how long the order would last were unavailable Sunday.

Why is so much snow falling?

Utah is currently beneath an “atmospheric river,” said Monica Traphagan, senior meteorologist with the National Weather Service.

“We’re tapping into strong tropical moisture coming from the Pacific and that’s streaming eastward into us,” she said.

While a lot of Utah’s storms typically come from the Pacific Northwest or farther north, this one is coming straight from the Pacific, bringing in warmer air, Traphagan said.

She referred to this long-lasting snowstorm as “climatologically unprecedented.”

How long will the storm last?

Much of Utah is under winter storm warnings and winter weather advisories in effect through Monday, according to the National Weather Service.

Heavy snow is expected to continue in the mountains through Sunday night and taper off Monday morning. The state’s northern mountains could continue to see snow through Monday afternoon, though, the weather service said.

All of Utah’s mountains could receive between 1 and 3 feet of snow, but 4 feet could fall in the Uintas, and the upper Cottonwood canyons could get a whopping 5 feet, the weather service said.

The Salt Lake Valley is under a winter storm warning until Monday at 5 a.m., and could see 4-6 inches of snow, according to the weather service. The forecast calls for snow until Tuesday, before tapering off Tuesday night.

The weather service said the snow coming from this storm is particularly heavy and wet and advised people to be careful while shoveling.

The St. George area will see a rainy New Year’s Day before rain and snow starts to fall Monday night and into Tuesday.