Avalanche forecast

Salt River and Wyoming Ranges

Bridger-Teton Avalanche Center
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Avalanche danger

Sun
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
No rating
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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Dangerous avalanche conditions persist! Weak layers of sugary facets were strained again by new snow which fell yesterday. Triggering a thick slab up to three feet thick is likely in some areas. What's worse, you may be able to trigger this type of avalanche from connected terrain above, beside or below a slope. Carefully evaluate slope angles and terrain to avoid this hazard.

Observations are limited in this zone with access challenged by poor snow cover at lower elevations. Let us know what you see through an observation or photo.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5

    Numerous recent  avalanches show that buried layers of faceted snow are likely to fail easily and from a distance. Added weight of new snowfall yesterday and today will further stress these weak layers, especially on wind loaded slopes. Slab depths above these weak layers were around 2 feet until the new snow yesterday. Slabs are thicker now with 6-18" of new snow recorded yesterday and could easily be well over three feet thick on wind loaded terrain over 9,000'. You will most likely find this problem type on slopes that face NE-N-NW above about 8,500’ where wind slab exist on the weak layers. This problem will be further strained by new snow arriving tomorrow.

    (12/5/2023)

    This slope failed from 40' away as skiers approached the top of the slope.  The current persisent slab problem is playing out with remote triggering from terrain above, below, or to the side of steeper slopes.

    Photo: Travis Baldwin

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5

    You may encounter wind slabs on exposed ridgetop areas that developed yesterday as well as older wind slabs from prior storms. A crust exists across many aspects and most elevations that formed prior to this storm will make these slabs reactive. Slab depths may be 2' thick on leeward slopes. Be aware that these slabs could propagate a surprising distance cross slope due to the poor bonding interface with the crust. You may be able to see older signs of wind loading  by looking for cornices and wind lines beneath yesterdays new snow. Given the widely distrubuted weak layers of snow, your best bet is to assume steep, exposed terrain harbors dangerously thick wind slabs.

    The crust that developed recently doesn't exist in all locations and seems to have developed 12/5-6 from very warm temps and possibly a period of rain shower activity. Regardless of the cause, where it exists it will be a problem.

Avalanche Discussion

New snow amounts yesterday were highly variable across this forecast area. The strain the new snow applied to the weak layers varies accordingly. While the new snow may not have generated widespread natural avalanches, it certainly tipped the balance towards easier triggering by a person on a snowmachine. The weak layer is showing all the signs of being a challenging and dangerous persistent slab problem. This type of problem is best dealt with by summoning patience and restraint. Riding is improving at upper elevations and will be best enjoyed on slopes or meadows under 20 degrees. 

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