Avalanche forecast

Sawtooth & Western Smoky Mtns

Sawtooth Avalanche Center
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Avalanche danger

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

You're most likely to trigger a large avalanche on steep slopes facing the northern two-thirds of the compass, especially in the southern part of this zone where the snowpack is thinner. Watch for and avoid fresh, stiff wind drifts, and anticipate sluffing in very steep terrain. 

Avalanche problems

  • Wind Slabs

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

    This zone has picked up 1-2 feet of snow since the weekend, with more expected today, creating two avalanche problems to keep on your radar:

    Wind slabs may have formed immediately beneath exposed upper elevation ridgelines and on the sides of cross-loaded gullies. The slabs could rest above weak crust/facet combinations on southerly aspects or small sugary facets on more north-facing slopes. They can be up to 2 feet thick and break wider than expected. 

    Loose snow avalanches or sluffs are possible in very steep terrain. Although most will be small, they may be large enough to knock you off your feet. Even small slides can be consequential above terrain traps such as gullies, creeks, and thick timber.

    (2/15/2025) This natural wind slab avalanche released on Feb 14th or 15th in the Boulder Mountains. The slide may have been triggered by cornice fall. Photo: Sawtooth Avalanche Center

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    2–2.5

    Slabs that formed in early February rest above a variety of ugly, widespread, weak layers (facets, surface hoar, crusts, and combinations). Before triggering an avalanche, you may or may not experience obvious signs of instability like snowpack cracking and collapsing or whumpfing. Persistent Slabs can release in surprising ways and break much wider than expected. You are most likely to trigger a dense, 2-4 foot thick avalanche where:

    • The slab is less than about 2' thick—relatively shallower spots may exist where the wind frequently blows, and the slab is not uniformly thick.
    • Any part of the slope you are on or connected to is steeper than about 35 degrees
    • The slope faces the northern 2/3 of the compass
    • A smaller wind slab or loose snow avalanche overloads the buried weak layers (problem above)

    (2/17/2025) Avalanche on Sun Mountain in a thin snowpack near Ketchum.  Photo: Sawtooth Avalanche Center

Avalanche Discussion

Given the recent snowfall and wind, continue to look for and avoid steep slopes with obvious recent wind loading or signs of instability, like snowpack cracking or collapsing. Avalanches involving recent snowfall have the potential to break into deeper weak layers, triggering a much larger persistent slab avalanche. 

Persistent slabs are most likely where the slab is thin, and buried weak layers are more easily affected by your sled, skis, or snowboard. The drainages around Smiley Creek are examples of locations where we suspect these thinner slabs exist. We've found fewer signs of instability in the deeper portions of this zone, including the northern and western Sawtooths and the western Smokys.

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