Avalanche forecast

Snake River Range

Bridger-Teton Avalanche Center
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Avalanche danger

Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Dangerous avalanche conditions have developed as new snow and wind will stress weak layers buried 2-3 feet deep above 7500'. Large human triggered avalanches will be most likely on north through east aspects where wind slabs can break on buried weak layers. Warming temperatures during the storm will create new snow instability at all elevations. Conservative terrain choices away from avalanche-prone terrain is advised, especially wind loaded slopes.

A Winter Storm Warning is in effect until 11:00 AM Saturday. 

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Recent snow combined with gradually warming temperatures will form soft slabs up to 12 inches deep across all elevations and aspects. Slab depths will increase with continued snowfall today.  Human triggered avalanches will be likely on any steep terrain over35°. Areas favored by the storm with higher snow amounts will be more unstable. Storm slabs could step down to buried weak layers triggering a larger avalanche. Look for obvious signs of unstable snow such as shooting cracks or upside down characteristics (denser snow towards the surface). 

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–2.5

    Weak layers of small persistent facets are buried 2-3 feet deep by soft slabs. Numerous D1-2 human triggered avalanches have been consistently reported on primarily N-NE-E-SE aspects above 7500’. Terrain where these weak layers are most reactive are being actively loaded by south/southwest wind. Any fresh formed wind or storm slabs can break on buried weak layers producing large propagation cross-slope or upslope. Wind loaded terrain will be the most dangerous today. Use careful route-finding to steer clear of wind loaded slopes. Keep in mind that steep, sheltered terrain also has the capability of producing larger avalanches on buried weak layers. Signs of instability such as cracking or collapsing may not be present before triggering a large avalanche. 

    Numerous large avalanches with significant propagation were reported yesterday in the adjacent Teton zone (See Recent Observations for more details).

    (2/14/2025)

    Persistent slab avalanche triggered yesterday showing the large propagation potential. Notice the cornice above the crown. Wind slab and persistent slab avalanches will overlap in their location today. 

Avalanche Discussion

Wind Loaded Terrain = Dangerous

Wind slab and persistent slab avalanches will overlap in location and distribution today. Any location where you find signs of wind loaded slopes with shooting cracks, collapsing, stiffened slabs or larger drifts also has the ability to fail on weak layers buried below the recent snow. By managing the persistent slab problem, you can manage the wind slab problem. Although persistent slab avalanches will be most likely and larger on wind loaded terrain, they can also occur on steep terrain more sheltered from the wind. Terrain over 35° steep should be approached cautiously due to the uncertainty of the peristent slab problem. 

Prior to this storm, we’ve seen avalanches triggered on the persistent weak layer (small near surface facets slightly above a stiff slab or melt freeze crust) across a variety of different terrain types. Large propagation potential has been observed since the weak layers initial burial Feb 6th. Multiple parties have been surprised with the continued reactivity of the weak layer. Knowing exactly which slope is capable of producing a persistent slab will be difficult. For this reason, it is encouraged to keep it conservative today as the weak layers are being stressed by the weight of rapid loading snow. Although less likely, larger avalanches failing on a deeper weak layer buried Jan 31st below hard slabs 3-4 feet deep could occur in isolated areas. Areas that are more prone include very steep, rocky, unsupported, or convex terrain.

Seek lower angle and less consequential terrain today while enjoying the powder storm riding. 

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