Boletín de aludes

Salt River and Wyoming Ranges

Bridger-Teton Avalanche Center
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Peligro de aludes

Sat
Alta montaña
3 · Notable
Límite del bosque
3 · Notable
Bajo el límite
Sin grado
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Desactualizado: este boletín caducó 3 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

Fresh snow combined with strong westerly wind will form sensitive wind slabs caused by poor bonding to a widespread crust. This new snow snow will also stress buried weak layers where larger avalanches are likely. Wind loaded terrain will be the most dangerous.  Intentional route-finding to avoid steep and wind loaded slopes will be necessary for safe backcountry travel today.

Problemas de aludes

  • Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Likely
    Tamaño
    1–2

    Numerous avalanches have been reported over the last week indicating that buried weak layers are still reactive. Added weight of new snowfall yesterday and today will further stress these weak layers, especially on wind loaded slopes. Slab depths above these weak layers are around 2 feet with locally higher amounts in upper elevations on wind loaded terrain. You will most likely find this problem on slopes facing NE-N-NW above about 8,500’. Remote triggering of avalanches from above, below, or to the side of steep slopes is possible today. 

    (12/5/2023)

    This photo accurately depicts the current persisent slab problem and remote triggering from gentle terrian above, below, or to the side of steep slopes.

    Photo: Travis Baldwin

  • Wind Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Likely
    Tamaño
    1–2

    6-8 inches of snow yesterday and an additional 6 inches possible today combined with moderate to strong W wind will form sensitive wind slabs on leeward terrain (N-NE-E-SE-S). A widespread crust across all aspects and most elevations formed prior to this storm will make these slabs reactive. Slab depths will be 12-16 inches deep on leeward slopes. Be aware that these slabs could propagate a surprising distance cross slope due to the poor bonding interface with the crust. Identify wind loaded terrain by analyzing the snow surface for rippled formations, large pillows, and cracking. Although less consequential, new snow could also slide easily on that crust even on steep slopes sheltered from the wind.

    (12/7/2023)

    Stout crust that lies directly beneath the new snow creating a poor bonding interface. 

    Photo: Alex Drinkard

Avalanche Discussion

Crusty Circumstances

The mountains experienced rapid warming for two days prior to this storm, creating a stout melt freeze crust across all aspects up to 10,000’ (possibly higher). The continuity of this crust across terrain makes the hair on the back of our neck stick up. Pay attention to the quality of new snow today. If this snow begins to firm up forming a cohesive slab then you’ll find unstable snow. Wind loaded terrain will certainly have this setup with W/SW winds consistently 40-50 mph yesterday.  Winds will decrease today and shift to the NW by this afternoon which could change the loaded pattern. Navigate through terrain carefully to avoid open, exposed slopes, such as ridgelines, where these wind slabs will be most reactive. This early season snowpack is becoming more complicated and unpredictable as buried weak layers are stressed by this new snow. Use conservative decision making to avoid steep terrain today as the snowpack adjusts.

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