Forecast for the Salt Lake Area Mountains

Nikki Champion
Issued by Nikki Champion for
Wednesday, December 14, 2022
The avalanche danger is CONSIDERABLE on all upper elevation aspects and mid and lower-elevation aspects facing northwest through east aspects where natural and human-triggered avalanches may break 1-4' deep and 200' wide, failing on a persistent weak layer of faceted snow. The avalanche danger is MODERATE on west-south-southeast aspects.

The north-facing slopes that are harboring old weak faceted snow surfaces are not to be messed with.

HEADS UP - The recent avalanche activity we have been seeing on the northern end of the compass at the mid and lower-elevation bands is a huge red flag. These elevation bands are especially dangerous right now, and slopes can be triggered remotely, or from below. There is enough snow above summer hiking trails where people could easily get caught and buried in terrain traps. Give extra caution to the mid and lower elevation bands today.
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Weather and Snow
This morning, light snow is falling in the mountains with temperatures in the single digits F at the highest elevations and low teens F at the trailheads. Winds are west-northwesterly and averaging 5-10 mph at mid-elevations, at uppermost elevations winds are averaging 30-35 mph, with gusts near 50 mph.
Today, an additional 1-3" of low-density snow will fall and temperatures will climb into the upper teens F. Winds at the 9000' ridgelines will blow from the northwest 10-20 mph gusting below 25 mph, and at the 11,000' ridgelines winds will pick up blowing 15-25 mph with gusts up to 55 mph.
Snow showers from this long-duration storm will gradually decrease, and may even end for a bit this afternoon before another cold system moves through the area late this evening. Starting around midnight snow showers should begin again, bringing an additional 3-6" of new snow. This unsettled weather has made for phenomenal riding conditions on lower-angle slopes.
With the addition of yesterday's snow and more snow overnight storm totals are up to:
  • Cottonwood Canyons- 19-46.5" (1.02-2.17" water)
  • Park City- 14-20" (0.51-1.10" water)
Recent Avalanches
Yesterday, there was an avalanche accident in the Pink Pine zone. We have put together a preliminary report for this accident, you can find it HERE.

Two skiers were exiting the Red Pine Drainage in Little Cottonwood Canyon. While doing this they were below the summer hiking trail. The first skier triggered the avalanche just northeast of Pink Pine Ridge (See map in report). As the second skier followed some distance behind the first, she saw there had been an avalanche. She started searching for the other skier with her transceiver, but then she saw him on the surface of the snow and called 911. The first skier sustained serious injuries. The avalanche failed on a North aspect at 7800'. The soft slab avalanche failed on the persistent weak layer 2.5-3' deep. The avalanche broke 60' wide and ran 300'. Drew, Greg, and Trent will be heading in to do an accident investigation this morning.
Avalanche crown for the accident in Pink Pine.

Earlier this week, there were a few more avalanches that occurred under 8000' on the north facing aspects in Daly Canyon near Park City, and in Summit Park near Parley's Summit. These lower-elevation north-facing aspects are areas where we have had avalanche accidents in the past. There is enough snow above summer hiking trails where people could get caught and buried in terrain traps. Continue to pay extra attention to the mid and low-elevation slopes.
Check out all the avalanches HERE.
Unstable test slopes in Bear Trap Fork.
If you see an avalanche please report it HERE.
Avalanche Problem #1
Persistent Weak Layer
There is plenty of weak sugary faceted snow (persistent weak layer) scattered on almost all aspects and elevations throughout the Wasatch Range. This persistent weak layer has now been buried under wind-drifted snow in upper-elevation terrain and capped by storm snow in the lower-elevation wind-protected areas.
In areas where the wind has loaded the slope, the slab could be anywhere from 1-4' feet deep and hard as a rock. We have dangerous avalanche conditions, and you can still trigger a season-ending slab avalanche failing on a persistent weak layer.
Out of the wind zone, at mid and low-elevation bands we have been seeing a lot of recent avalanche activity, including an avalanche accident yesterday at 7800' on a north-facing aspect. This is a huge heads-up that these zones are equally as dangerous as the upper elevation bands. With all of the new snow, a sensitive soft slab avalanche could fail on top of the weak facets up to 3' deep. There is great skiing to be had on low-angle slopes and I will be staying away from steep northwest-north-east-facing slopes at all elevations.
Avalanches are slightly less likely on solar aspects because of the presence of ice crusts. There is a MODERATE avalanche danger on west-south-southeast aspects. Keep an eye out for higher-elevation south-facing areas that may have weak faceted snow under a stiffer slab of new or wind-drifted snow.
Avalanche Problem #2
New Snow
The Salt Lake Area mountains have now received anywhere from 20-50" of new snow over the last three days. New snow avalanches will remain sensitive in steep terrain at all elevations on all aspects. All of this new snow may create both sensitive soft slab avalanches and long-running loose dry avalanches in steep terrain.
These new snow avalanches may step into the old-faceted snow-producing significantly larger avalanches.
Avalanche Problem #3
Wind Drifted Snow
Since yesterday, the northwest winds have increased drastically at 11,000' and have likely been transporting snow at the upper elevations. For the snowpack, when the winds drift snow, it's the same as if snow is falling out of the sky. The snowpack doesn't care where the snow comes from, it feels the added weight. So, on northerly-facing slopes, these winds have added snow and weight, and stress to the avalanche problem listed above. Any wind slab avalanche that you trigger has the potential to step down into deeper weak layers in the snowpack.
What to do? Look for evidence of fresh drifts and wind slabs that look wavy, rounded, smooth, and pillowy, and avoid those slopes.
Additional Information
Mark Staples has also written a season summary HERE.
Check out this forecast discussion.
General Announcements

This information does not apply to developed ski areas or highways where avalanche control is normally done. This forecast is from the U.S.D.A. Forest Service, which is solely responsible for its content. This forecast describes general avalanche conditions and local variations always occur.