Boletín de aludes

Togwotee Pass

Bridger-Teton Avalanche Center
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Peligro de aludes

Sat
Alta montaña
2 · Moderado
Límite del bosque
2 · Moderado
Bajo el límite
Sin grado
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Desactualizado: este boletín caducó last year. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

New snow combined with east to northeast wind has formed slabs up to a foot deep on less commonly wind loaded slopes. Larger avalanches failing on buried weak layers remain possible on very steep, rocky, and wind affected slopes. Steer clear of complex terrain where these problems overlap and triggering an avalanche is more likely.

Problemas de aludes

  • Wind Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1–1.5

    Recent snow combined with atypical northeast to east wind has formed slabs up to a foot deep on slopes less commonly wind loaded. Look for signs of wind loaded slopes such as shooting cracks, stiffened surfaces, or large pillows. Triggering an avalanche will be most likely on steep, open and exposed terrain to the wind. The higher you climb in elevation, the higher the likelihood of finding unstable wind slabs. If skies clear and slopes receive direct sunlight, recent snow could become more unstable and easier to trigger.

    This type of cracking on wind-loaded indicates unstable snow.

    Photo: BTAC

  • Deep Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    2–3

    Triggering an avalanche on buried weak layers where the overlying slab is 2-3 feet deep is possible on very steep slopes over 35° in the upper elevations. Signs of instability such as cracking, collapsing, or recent avalanches may not be present before triggering a large, dangerous avalanche. Multiple tracks on a slope do not indicate stability with this problem type. Terrain that remains most suspect includes complex, very steep, rocky, and wind affected slopes where thin spots can impact the buried weak layers. Triggering a wind or storm slab is capable of stepping down to buried weak layers and producing a larger avalanche.

    These persistent slab avalanches are capable of propagating widely across or up a slope. For this reason, it is not out of the question to trigger larger avalanches with slab depths 5+ feet as a result of hitting the thin, shallow spot of the slope. Heavily wind affected slopes are where these avalanches could occur. On February 10 a very large persistent slab avalanches occurred on the wind loaded east face of  Lava Mountain. 

    (3/1/2025)

    Large avalanche that failed on persistent weak layers 2-3 feet deep in complex terrain. 

    Photo: Dakota Richardson

Avalanche Discussion

Snowfall amounts yesterday were below forecasted totals in this zone (unfortunate for powder enthusiasts). For this reason, the avalanche danger rating has been dropped. The weather is difficult to predict and yesterday provided a good reminder of why it is important to assess the weather and snow yourself rather than rely solely on the avalanche danger rating.  

You may notice that we combined the persistent slab problem into the deep persistent slab problem. The travel advice for both problems matched up with one another. The more complex the terrain, the higher the likelihood of triggering weak layers buried in the middle or bottom of the snowpack. Impacting any weak layer and triggering a hard slab avalanche of any depth holds serious consequnces. The main message is that large or very large avalanches can be triggering where the overlying is thin and easier to impact, which could be 1-3 feet deep. Last week, two avalanches were reported on Grouse and Mt Leidy that failed on basal facets near the ground on very steep, complex terrain. These weak layers could be reactive still. The snowpack has not fully transitioned to a stable spring snowpack depsite last weeks warm temperatures. 

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