Bulletin d’avalanche

Salt Lake

Émis le Feb 7, 2024valide jusqu’au Feb 8, 2024Utah Avalanche Center

Danger d’avalanche

Alpin
Limite forestière
Sous la limite forestière

Périmé — ce bulletin a expiré 3 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

UPDATE 1:36 PM: The UAC has issued an AVALANCHE WARNING. Avalanches are happening now. Strong winds and heavy snowfall have overloaded the mountains. The avalanche danger has reached HIGH danger and traveling in avalanche terrain is NOT recommended.

The avalanche danger is CONSIDERABLE across the mid and upper elevationsfor several avalanche problems. Pick your poison: Hard and soft slabs of wind-drifted snow. Soft slabs of new snow. Or you could trigger an avalanche that fails on a buried persistent weak layer. It's complicated and very dangerous.

In any case, the avalanche you trigger is likely a few hundred feet wide and could be 3 to 6 feet deep.

Problèmes avalancheux

Wind Slabs
N
NE
E
SE
S
SW
W
NW
Alpin
Limite forestière
Sous la limite forestière
Probabilité
Likely
Taille
3
It's been 60 straight hours of south winds blowing 10-25 mph with gusts into the 20s and 30s. These are the perfect speeds for drifting snow onto lee slopes. These winds, combined with feet of dense, heavy snow, have created monster soft and hard slabs of wind-drifted snow in the starting zones. These will not be small avalanches. If caught in this avalanche, you will instantly feel like you're strapped to the front of a speeding train. All it will take is one tree, and you're done.

If you trigger a wind-drifted snow avalanche, it's possible it can step down into deeper weaker layers, creating a much larger avalanche.

Travel Advice: Very dangerous avalanche conditions. Traveling in avalanche terrain is NOT recommended. This means being on or under any steep wind-drifted slopes.
Storm Slabs
N
NE
E
SE
S
SW
W
NW
Alpin
Limite forestière
Sous la limite forestière
Probabilité
Possible
Taille
2
Yesterday, one observer found an avalanche that failed within the new snow on the Silver Fork Headwall. This avalanche was roughly 2 feet deep and 100-200 feet wide and large enough to bury a person. Another person was caught and carried in a new snow avalanche on Patsy Marly. I expect that with more snowfall on the way, our new snow will remain active today and tomorrow.
Persistent Slabs
N
NE
E
SE
S
SW
W
NW
Alpin
Limite forestière
Sous la limite forestière
Probabilité
Likely
Taille
3
It's complicated. But it's also so simple.

The complicated part: is where and when do you trigger an avalanche on our persistent weak layer? Our weak layer is now buried roughly 2-6' deep with a thick, hard slab of snow above. It seems the most likely spot to trigger an avalanche will be in a steep thin rocky area. However, yesterday's avalanche on Sugarloaf shows this is still a major problem outside of thin and rocky places.

One slope is stable and then another can produce a large, deep and dangerous slab avalanche. How do you know or manage which option you get? I honestly do not know how to manage this problem or provide any advice in dealing with this problem with how variable the snowpack is.

Here comes the simple part. I would avoid avalanche terrain for now and let the snowpack adjust and settle more. This added weight is a good thing for the snowpack long-term. However, today the added weight is only adding stress and increasing the likelihood of triggering an un-survivable avalanche.

There has been many close calls over the past few days and I fear our luck is going to run out. Please avoid avalanche terrain today and be patient.

Recent Activity

Yesterday's avalanche that caught my eye was a remotely triggered avalanche from a piece of terrain in upper Little Cottonwood on Sugarloaf Peak that represents a backcountry snowpack. Two patrollers were heading out to run routes and got the slope to collapse. The avalanche was 2 feet deep and 300 feet wide, failing on faceted snow (picture below).

Two people were caught and carried yesterday. One in White Pine involving faceted snow. One on Patsy Marly. Both people were luckily not injured.

Across the lower elevations, damp, wet, and heavy snow produced widespread roller balls and wet-loose avalanches.

Snow and Weather

Another 4.0-9.5 inches of new snow fell overnight, containing 0.40-1.24 water. This brings our six-day storm total for the Upper Cottonwoods to roughly 48 inches of snow with 5.10 inches of water weight.

This morning, it's snowing, and the southerly winds continue their onslaught, blowing 10-20 mph with gusts into the 20s and 30s. Mountain temperatures range from 20-25 °F.

Today, we should see continued snowfall throughout the morning on a southerly flow with winds blowing 10-20 mph. By this afternoon, the wind will finally change direction, blowing from the west and then the northwest. Once the wind changes, the snowfall is expected to be heavy at times. Throughout the day today, we could see an additional 7-17 inches of new snow (0.45-1.2 inches of water)

Additional Info

If you trigger an avalanche in the backcountry, AND NO ONE IS HURT or needs help, please notify the nearest ski area dispatch to avoid a needless response by rescue teams. If someone is injured or you need help, call 911.

Salt Lake and Park City – Alta Central (801-742-2033)
Canyons Resort/PCMR Dispatch (435 -615-1911)

General Announcements

CLICK HERE FOR MORE GENERAL INFO AND FAQ

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.

Observations and Avalanches

Backcountry Emergency Procedures