Bulletin d’avalanche

Banner Summit

Sawtooth Avalanche Center
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Danger d’avalanche

Fri
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

Human-triggered avalanches are possible on steep slopes. They are most likely as you climb in elevation and in areas where the wind has drifted snow or stiffened the snow surface. Cracks shooting in front of your skis or sled mean the slope you're on may be unstable. 

Problèmes avalancheux

  • Storm Slabs

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

    New snow and wind are forming thin storm slabs. These slabs will be thicker at upper elevations where snow totals, and wind speeds are greater. Anticipate thicker slabs on the northern half of the compass as the strongest winds blew from the SW-S-SE. Slabs formed over various potentially weak surfaces including facets and crust + facet combinations. Expect freshly formed slabs to be easy to trigger on steep slopes. Some may be triggered from lower angled terrain above, below or to the side of a steep slope. 

    New snow alone isn't a problem, but rapid settlement, wind stiffening, or drifting can quickly change the equation. Look for signs of wind loading, like fresh cornice growth and dunes or ripples in the snow surface. Feel for stiffer snow and watch for obvious signs of instability, like snowpack cracking or collapsing. You can always reduce your risk by sticking to lower-angled terrain and avoiding slopes that end in terrain traps like cliffs, trees, or creek bottoms. 

Avalanche Discussion

Storm totals are expected to reach 4-8" by midday. Most of this precipitation likely fell as wet, heavy snow or rain at lower elevations. In these areas be aware of how deeply you are sinking into wet snow. Boot top or deeper mush could be a problem in very steep terrain.

Snow totals increase as you climb higher and wind plays a leading role in slab formation as you enter more open, exposed terrain. Most snow fell during moderate SE-S-SW wind which likely built thicker and more sensitive slabs on the northern half of the compass. Expect some of these wind-loaded slopes to be easy to trigger where slabs formed over small facets or crust/facet combinations. 

We've enjoyed a stretch of spring-like conditions and good stability, but it's time to snap back to reality (it is still winter after all.) This is the first in a series of winter storms that have the potential to build a formidable slab in many areas. Today is a good day to approach the mountains with curiosity. How is the new snow bonding? Use quick hand pits and small inconsequential test slopes to find out, and be prepared to dial back your terrain choices accordingly. 

Régions couvertes