Bulletin d’avalanche

Banner Summit

Sawtooth Avalanche Center
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Danger d’avalanche

Sun
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré last year. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

You could trigger an avalanche on steep slopes where the wind has built thick drifts or stiffened the snow surface. You may be able to trigger avalanches remotely—from flat terrain below, above, and to the sides of steep slopes. Cracks shooting in front of your skis or sled mean the slope you're on may be unstable. 

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    Continued snow showers and moderate winds today will build thicker slabs where the wind has been at work transporting snow. You are most likely to find this problem at upper elevations, but you could find trouble in wind-exposed terrain features (ridgelines and gullies) at middle elevations. Anticipate thicker slabs on the northern half of the compass; these slabs have formed over various potentially weak surfaces, including facets and crust + facet combinations. Expect freshly formed slabs to be easy to trigger on steep slopes, especially on NE, N, and NW-facing slopes. You could trigger one of these slides from lower-angled terrain above, below, or to the side of a steep slope. 

    Don't rule out the possiblity of finding trouble in more sheltered terrain, especially on the northern half of the compass where recent snowfall fell onto a weak old snow surface. 

    (3/13/2025)

    Remotely triggered storm slab on Paymaster Peak at 9200' NW aspect. This was triggered from ~100' feet away on a ridgeline.

    Photo: Sawtooth Avalanche Center

Avalanche Discussion

You are most likely to trigger an avalanche where the wind has drifted new snow into thick drifts. We are trending toward a persistent slab problem, and freshly formed wind slabs may exhibit similar characteristics. Avalanches could break wider than expected and could be triggered from lower-angled terrain below, above, or to the sides of steep slopes where recent snowfall fell onto a weak, old snow surface. NW, N, and NE aspects harbor the weakest, sugary snow below recent snowfall. Approach steep slopes with a degree of suspicion—especially where you find or suspect the wind has stiffened the snow surface or built thicker drifts. Don't completely rule out finding trouble in more sheltered terrain, where recent snowfall fell onto a weak old snow surface. Watch for signs of instability, like snowpack cracking or collapsing, which indicate an unstable snowpack.

On solar slopes, new snow has bonded well to the old crusty surface below. Watch for a rippled or textured surface; these are signs the wind has been at work, and you may find thicker, easier-to-trigger wind slabs as you climb into the upper elevations near ridgelines or wind-exposed terrain features.

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