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Forecast for the Salt Lake Area Mountains

Nikki Champion
Issued by Nikki Champion on
Wednesday morning, December 29, 2021
The avalanche danger is CONSIDERABLE on mid and upper elevation aspects facing west through north and east, where strong winds and recent snowfall have created dangerous avalanche conditions. Human-triggered avalanches are likely. Any natural or human-triggered avalanche can be 2-6' deep, over a few hundred feet wide, and likely unsurvivable.
Most avalanche accidents and fatalities occur at a CONSIDERABLE danger rating. Low-angle terrain remains the safest, and best option today.
There is a MODERATE avalanche danger on mid and upper elevation aspects facing southwest, south, and southeast. Low elevations have a MODERATE avalanche danger.
Low
Moderate
Considerable
High
Extreme
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Special Announcements
There will be avalanche mitigation work taking place in the Murdock Peak Area near the Super Condor Express chairlift. Please stay clear of that area.
Weather and Snow
Under cloudy skies, snow has lightly begun falling in the mountains. Temperatures remain cold, with current mountain temperatures in the single digits °F. Winds are light, and are blowing from the west-southwest at speeds of 5-15 mph with occasional gusts up to 20 mph. The last 24 hours was the first reprieve in the strong winds, in about six days. Since yesterday morning, the mountains picked up another trace to 2.5" of snowfall.
Today will be mostly cloudy with another storm moving into the area this afternoon. Heavier snowfall should begin after 3 PM, with 6-12" of snow possible by tomorrow morning. Temperatures will climb out of the single digits to the upper teens and low 20s °F. Throughout the day winds will remain light to moderate, and begin picking up into the afternoon. The west-southwesterly winds will blow at speeds of 10-20 mph with occasional gusts up to 35 mph. The bad news is, as this storm becomes more southwesterly, the winds will continue to increase overnight with upper elevation gusts up to 50 mph.

Many people have asked me what happened to our epic storm? Where is all the snow? Well, Jim Steenburgh covered this question in his blog HERE. Tuesday morning Trent decided to add up the water amounts for the past five days. Talking to the Alta Avalanche Office, they manually measured at Alta Collins 9,600', 4.14 inches of water for the past five days. In the Uintas, the Trial Lake weather station reads 5.4 inches of water. If you take the normal Utah snow ratio of 12:1, it snowed 50 inches at Alta and 65 inches at Trail Lake. Other parts of the state also ended up with inches of water and feet of snow. Despite the annoying south winds, the water and snow totals are impressive.
Recent Avalanches
No new avalanches were reported in the backcountry yesterday. Ski resorts are still getting explosive triggered results within the upper elevation west through north through east facing terrain.
Photo of explosive triggered hard slab 10,700’ N facing. Upper Little Cottonwood Canyon.
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Avalanche Problem #1
Persistent Weak Layer
Type
Location
Likelihood
Size
Description
The past week of heavy snowfall and strong winds continue to overload a buried persistent weak layer of faceted snow down near the ground. This layer exists on mid and upper elevation aspects facing west through north and east. Any avalanche failing on this layer may break down 2-6' deep (possibly deeper), propagate hundreds of feet wide, and run downhill thousands of feet. While the avalanche danger dropped to considerable today, the consequences remain the same; these are large, deadly, and destructive avalanches.
A few words of caution:
  • Obvious signs of instability may not be present today: you may or may not see or experience shooting cracks or audible whumping. The danger still exists.
  • Tracks on the slope offer zero signs of stability. Avalanches will take out multiple existing tracks.
  • You can trigger these avalanches remotely (from a distance) or from below. Give ridgetops a wide berth.
  • Any fresh wind slab or new snow avalanche may step down into this older layering of weak snow.

We are on the back end of the parabola as shown below. While we may not be seeing as many obvious signs of instabilities like cracking, collapsing, and recent avalanche activity. The avalanche danger still very much exists. Over the last five days, the danger was very obvious, with high winds and new snowfall. Today that avalanche danger may not seem as obvious, and I fear that people may push out onto steeper west through north through east-facing slopes, get away with it, and think that we are in the clear. We are not in the clear. This avalanche problem is the real deal and should be avoided with large safety margins. Avoidance is the key.
Avalanche Problem #2
Wind Drifted Snow
Type
Location
Likelihood
Size
Description
Strong winds have created both hard and soft slabs of windblown on all aspects at the mid and upper elevations. Although the winds have been mainly from the west/southwest, winds this strong can channel snow around terrain features and create fresh drifts on all aspects, including well-down off of ridge lines. You may even find fresh wind drifts at unusually low elevations below 8,000'.
Today look for slopes with any signs of wind drifted snow, such as cracking, hollow noises, and pillow-shaped snow, and avoid those slopes.
Additional Information
Craig Gordon, Mark Staples, Trent Meisenheimer, Toby Weed, and Brett Kobernik discuss the current avalanche situation. They discuss some things we know and some things we don't know.

General Announcements
Who's up for some free avalanche training? Get a refresher, become better prepared for an upcoming avalanche class, or just boost your skills. Go to https://learn.kbyg.org/ and scroll down to Step 2 for a series of interactive online avalanche courses produced by the UAC.
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.