Bulletin d’avalanche

Banner Summit

Sawtooth Avalanche Center
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Danger d’avalanche

Sun
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré 2 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Dangerous avalanche conditions exist. Large avalanches may release on their own in windy terrain. You could trigger slides remotely—from flat terrain below, above, and to the sides of steep slopes.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2

    Snowfall and active wind-loading continue to build sensitive wind slabs. These 1.5-3' thick slabs will be easy to trigger and may release naturally. Cornices will grow large and unstable and may trigger large avalanches as they impact the slope below. 

    Expect to find slabs near or just below ridgelines and along mid-slope ribs and gullies. Cracks shooting in front of you mean you've found a sensitive slab. Some slabs have formed on slopes that harbor weak, sugary facets or crust + facet combinations; these are especially touchy and may break wider than expected. 

    You can manage your exposure to this problem by identifying and avoiding wind-loaded slopes. This includes the paths and runouts of steeper avalanche paths that threaten you from above. 

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1.5–2

    In areas more sheltered from the wind, persistent slab and loose snow avalanches are possible. Storm totals will reach 14-25" by day's end. This snow sits atop a mix of weak snow surfaces, including surface hoar, facets, and facet + crust combinations. These layers exist on many slopes, the worst of which are found at middle and low elevations. 

    A kiss of wind, mild temperatures, or a brief bit of sun is all it takes to consolidate the storm snow into a touchy slab. Although smaller than the thicker wind slabs described above, this problem will be tricky and harder to manage. Slabs may release in surprising ways and break wider than expected. They may be triggered from a distance—above, below, or to the sides of steep slopes. It's hard to predict which slopes are unstable, so build a wide safety margin to handle the uncertainty. 

    Expect heavy sluffing on many steep slopes. Triggered slides of any form may quickly gain mass as they easily entrain the weak facets below.

Avalanche Discussion

Heavy snowfall, wind, and widespread weak snow layers are creating dangerous and tricky conditions. Storms continue today, ease into tonight, and ramp up again on Sunday and next week. Expect to see natural avalanches on steep slopes, especially those loaded by the wind. Your odds of triggering a slide continue to increase as slabs develop in areas mostly sheltered from the wind.

Finding safe places to play is getting harder, and conditions are ripe for getting surprised. Enjoy the new snow, but pick your tours and rides carefully. Give large avalanche paths a wide berth, and don't underestimate the consequence of even smaller avalanches that could push you into terrain traps, such as thick trees, cliffs, and creek bottoms. 

Régions couvertes