Post-Christmas snow triggers winter storm warning for Utah's mountains

SALT LAKE CITY — Several Utah communities, including Tooele and Park City, as well as benches along the Wasatch Front, experienced a white Christmas on Wednesday, but the holiday storm system provided a moisture gift that keeps on giving.

The National Weather Service issued a series of winter storm warnings and winter weather advisories across the state Thursday, some of which have now been extended to continue through Saturday.

Federal meteorologists note that parts of the Wasatch Mountains and other nearby ranges have a strong probability of receiving another 18 inches of snow or more over the next few days.

Lingering precipitation

Not everyone in Utah got a white Christmas, but the Christmas storm delivered a nice dose of precipitation after another dry stretch across the state.

Pleasant Grove collected 0.58 inches of precipitation to lead all valley communities, while Kaysville added 0.43 inches. Salt Lake City collected 0.29 inches of precipitation, ending the day just under an inch of its December normal with less than a week left in the month.

KSL meteorologist Matt Johnson explained the Christmas storm was too warm for valley snow in some parts of the state, which models indicated could happen. More importantly, it pushed out the high-pressure ridge over the state, opening the door for more precipitation this week.

Waves of rain and snow showers are forecast to pass through Utah over the next few days. Some of these will be light, but there may be heavy bands of precipitation at points, too, Johnson said.

Storm accumulations

The on-and-off showers are a little more difficult to project because they aren't as organized as a traditional winter storm. However, the winter storm warning — issued for the Wasatch, West Uinta and Wasatch Plateau/Book Cliffs mountains — notes that chances for significant snow accumulation are high in certain areas.

The Upper Cottonwood Canyons, the mountains by Ben Lomond Peak and the Bear River range all have a 70-90% probability of exceeding 18 inches of snow by the end of Saturday. Those areas also have a decent shot — about 20-30% — of exceeding 30 inches, the weather service says.

"The highest chances are farther north in the Bear River Mountains," the alert states. "The snow will be denser than normal, with warming temperatures and snow levels rising through the weekend."

A winter weather advisory was issued for the central mountains, which are expected to receive 6-12 inches of snow over the next few days. Another advisory was issued for eastern Box Elder County, where "widespread snow" in the valley could cause issues on Thursday.

KSL Weather models suggest that most parts of the Wasatch Front could collect 0.5-1 inches of precipitation or more between Thursday morning and Saturday afternoon, most of which will fall as rain but some snow already fell on Thursday. Parts of central and eastern Utah could also come away with 0.1-0.5 inches; rain and snow are less likely in southern Utah, which the lingering showers could skip.

Storm impacts

Johnson said some of the showers could come during traditional commuting hours or when people are returning from holiday getaways.

Utah Department of Transportation officials issued a road weather alert, advising drivers to use "moderate" and "high" caution on roads across Utah's northern half. Aside from possible issues tied to road snow in northern Utah, traction laws were enforced across multiple mountain passes on Thursday:

• Big and Little Cottonwood canyons in Salt Lake County.
• U.S. 91 through Sardine Canyon in Box Elder/Cache counties.
• State Route 224 at Empire Pass in Summit County.

Only vehicles with four-wheel drive or chains are allowed on roadways when restrictions are in place. Chain restrictions could be extended or enforced in other areas at points throughout the next few days.

As for those recreating in the snow, "considerable" avalanche danger persists across the Wasatch Mountains, according to the Utah Avalanche Center. The agency has received a few avalanche reports over the last few days, including one that temporarily buried a snowmobiler in the Franklin Basin area of Uinta-Wasatch-Cache National Forest on Christmas Eve.

The agency's forecasters say avalanche danger could rise as new snow falls on "weak layers" built up on the mountains. They recommend people avoid slopes of 30 degrees or more.

More on the way?

Another storm could impact the state between Sunday and Monday, the National Weather Service advises. It's unclear how much additional moisture that would provide.

The skies will clear up after that. Dry and cool temperatures are currently forecast for the end of 2024 and the start of 2025.

Full seven-day forecasts for areas across Utah can be found online, at the KSL Weather Center.

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