Bulletin d’avalanche

Snake River Range

Bridger-Teton Avalanche Center
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Danger d’avalanche

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

Points saillants

The chance continues for skiers and riders to trigger slab avalanches in steep terrain at the mid and upper elevations. While the likelihood of triggering a slide has decreased, isolated areas could still fail on approach or after a slope has a few tracks on it.  Snowpack evaluation and/or conservative terrain choices are recommended for safe mountain travel.

Problèmes avalancheux

  • Persistent Slabs

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

    A persistent weak layer of faceted snow was buried by last week's storm.  Slabs avalanches could be triggered on this layer in steep avalanche terrain. These slabs could be soft or hard and have depths to three feet in upper elevation terrain that was wind loaded and depths to two feet in very steep mid elevation terrain.  Areas where weak snow may fail are most likely to be found in terrain with a northerly component in aspect as that's where the old weak snow was most widespread although cold shaded areas on other aspects cannot be ruled out. 

Avalanche Discussion

The current snowpack is straightforward, newer snow sits upon old snow. Last week's storm brought the shallow early season snowpack to near average depths. The older snowpack was made up mainly of faceted snow.  Old snow on south facing terrain that receives direct sunlight in December was shallow and limited to high slopes while cold, shaded and north facing terrain had ample amounts of faceted snow reaching down into the lower elevations. The newer snow sits on top of this older weak snow and a widespread natural avalanche cycle occurred during the storm event.   Although the snowpack has ultimately been gaining strength with the warm temperatures during the last few days, human triggered avalanches remain possible. Observations continue to come in of people causing the snowpack to collapse which indicates that areas of instability persist and in steep terrain, avalanches may still be triggered. Be conservative and avoid very steep terrain that is underlain by the old weak snow.  Also, keep in mind it is a shallow snowpack with hazards of rocks and trees lurking just under the surface.  Today's forecast of minimal snow amounts, light winds and mild temperatures are not expected to significantly change the avalanche danger.

Régions couvertes