Winter storms are expected to hit Utah beginning Thursday and continue through Christmas, bringing a few inches of snow to the valleys and a foot or two to the mountains.
According to the National Weather Service, there’s a 50% chance of precipitation on Thursday in Salt Lake City, rising to an 80% chance after 3 p.m.
On Thursday night, however, there’s a 100% chance of rain and snow, becoming all snow after midnight. There could be 2-4 inches of accumulation.
The storm will continue on Christmas Eve and Christmas Day. There’s a 90% chance of snow on Friday, and a 70% chance on Friday night and Saturday. Valleys along the Wasatch Front can mostly expect 1-3 inches, with higher accumulations on the benches.
That won’t be the end of it, as the series of storms continues to roll through Utah. Snow is likely Saturday night through Monday night — and it could continue into Tuesday — bringing a few more inches.
Highs are forecast in the upper 30s through Saturday and in the low 30s on Sunday and Monday. On Tuesday, highs in the upper 20s are expected.
Avalanche danger
The mountains will get hit much harder. The U.S. Forest Service and the Utah Avalanche Center issued a warming that the storm “will create dangerous avalanche conditions on steep mountain slopes.
“Heavy snowfall will overload slopes, natural avalanches will occur, and people will likely trigger large, dangerous and destructive avalanches if they venture into avalanche terrain,” the center advised.
Hikers and skiers should make sure everyone in their group has avalanche rescue gear and knows how to use it; cross steep slopes one person at a time while others watch from a safe place; and avoid being under any slopes, even very small ones, the center said in a news release.
The weather service has issued a winter storm warning from 6 a.m. Thursday until 5 a.m. Saturday for the Wasatch Mountains, the Western Uinta Mountain, the Wasatch Plateau/Book Cliffs, Mirror Lake Highway, and the cities of Alta, Brighton, Mantua, Logan Summit and Scofield. Heavy snow — 1 to 2 feet — is possible, and there could be more than that in some areas. Wind gusts as high as 40 mph are possible, resulting in blowing and drifting snow.
The heaviest snowfall is expected Thursday evening through Friday morning. Travel could be “very difficult to impossible” in some areas, including along Interstate 80 in the mountains, according to the weather service.
Air quality to improve
The incoming storms are expected clear out in valley inversions and improve Utah’s air quality. The Utah Department of Environmental Quality’s forecast calls for an air quality index of orange, or “unhealthy for sensitive groups,” in Salt Lake, Cache, Davis and Weber/Box Elder counties before a storm arrives late Thursday; it’ll be yellow, or “moderate,” in Duchesne, Uintah and Utah Counties.
Once the storm begins though, it’ll be green, or “good,” across the state on Friday, the forecast advises.
The storms will affect most of the state but will bring mostly rain to southern Utah — maybe mixed with a bit of snow. In St. George, there’s a 40% chance of rain on Thursday, 80% on Thursday night, 90% on Friday, 60% on Friday night, and 40% on Christmas Day. It could continue to rain Sunday, Monday and possibly Tuesday.
Temperatures will be in the mid-50s in St. George through Christmas Day, then fall into the 40s Sunday-Tuesday.