Avalanche forecast

Sawtooth & Western Smoky Mtns

Sawtooth Avalanche Center
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Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Highlights

Watch for and avoid steep slopes with stiff, wind-drifted snow. You're most likely to find wind slabs in upper elevation and alpine terrain. Wind-protected slopes with soft snow on the surface are unlikely to produce avalanches. 

Avalanche problems

  • Wind Slabs

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

    Saturday, Ben intentionally triggered a 6-18" thick wind slab that broke about 100' wide on a SE-facing, alpine slope in the northern Sawtooths. Also on Saturday, a group triggered two wind slabs south of Copper Mountain on steep, upper elevation, northerly aspects. The slides were 6-18" thick and broke 40-100' wide. They released near exposed ridgelines, and both slides broke wider than your "run of the mill" wind slab due to a weak layer of facets buried directly beneath the fresh wind-transported snow. 

    Why does the current crop of wind slabs still deserve respect:

    • The fresh slabs are perched above variable snow surfaces, including potential weak layers (facets, crusts, surface hoar) that formed during our extended January dry spell on some aspects and elevations. Slides could break above you and be wider than anticipated, and the weak layers are slowing the stabilization process. 
    • Today's expected moderate to strong winds may continue sifting snow onto existing drifts and slabs, including "spin drifting" snow onto aprons low in alpine cirques.

    While these wind slab avalanches probably won't bury you, they're too big to tangle with. They could easily take you for a ride, pile you into trees, or wash you into a terrain trap. The possibility of wind slabs breaking above you or wider than expected makes them difficult to manage.

    How should we travel today?  The simple elegant solution is to steer clear of this tricky problem. Watch for drifting and changes in the surface snow texture. The variable NW-N-NE winds may have formed slabs in unusual locations, including on aprons at the bottom of large cliff bands or steep faces. If the snow surface gets stiff and supportable or you see cracks shooting out from your boards or skis, stick to gentle terrain.

    (1/22/2022) North winds following Thursday's 6" of new snow created sensitive wind slabs. These are failing on weak snow surfaces that formed during the ongoing dry spell. This wind slab was intentionally triggered in alpine terrain in the Sawtooths.

Avalanche Discussion

The wind slab problem described above is front and center today, but there are a couple of other things to keep in mind:

  • Cornices: Use extra caution around cornices, which—thanks to a very snowy + windy December—have grown exceptionally large this early season. Many observers have noticed cracks near larger cornices where these beasts are peeling away from steep ridgelines. Stepping through the surface snow into one of these cracks can lead to an awkward moment indeed.
  • Deep persistent slabs: Weak faceted snow exists near the ground on shaded NW-N-NE-E facing slopes at middle and upper elevations. In this zone, it's buried beneath a very dense, 5-7 foot thick slab. Triggering this layer would take a dose of very bad luck, but local professionals and savvy backcountry riders are still leery of big, open, "prime-time" slopes (around 35-45 degrees) that are wind-affected and rocky. 

Catch up on what happened (or didn't happen) this past week in Scott's latest Weekend Update.

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