Bollettino valanghe

Togwotee Pass

Bridger-Teton Avalanche Center
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Pericolo valanghe

Mon
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
Senza grado
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Non aggiornato — questo bollettino è scaduto 2 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

New snow and wind will make it possible to trigger an avalanche up to a foot deep in steep wind loaded terrain above 9,000’. Larger avalanches failing on weak layers buried 2-4 feet deep are also possible in very steep terrain. Carefully evaluate the new snowfall for signs of instability such as cracking or recent avalanches and give very steep terrain a wide margin given the potential for deeper avalanches.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    New snow and moderate winds out of the west/southwest will form fresh soft slabs up to a foot deep in leeward terrain above 9,000’. These slabs will be most sensitive to triggering while they are forming and could easily release under the weight of a rider. Be on the lookout for signs of wind loading including blowing snow and fresh drifts of denser snow. Cracking, collapsing, and recent avalanches are signs that the new snow is unstable. Consider moving to low angle terrain if you observe these signs.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–2.5

    Weak snow that formed during a dry period in the second half of January has been buried 2-4 feet deep by snowfall from the early February storms. These slabs sit on a variety of interfaces, including crusts on solar aspects and facets on shaded aspects. The likelihood of triggering slabs at this interface has decreased over time. However, activating this layer may still be possible in very steep, rocky, and wind affected terrain. Large triggers such as a surface avalanche, cornice fall, or multiple riders on a slope will increase the odds of impacting these weak layers in the middle of the snowpack. While the chances of triggering are low, it remains important to stack the odds in your favor by following safe travel protocol. Travel one at a time across steep terrain, use islands of safety, and communicate with your partners.

    (2/11/2025)

    An avalanche failing on weak snow formed during the dry period at the end of January.

    Photo: Bridger-Teton Avalanche Center

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    2–3

    Weak snow exists near the ground above 9,000’. This snow is buried 5 feet deep on average. Although triggering an avalanche at this depth is very unlikely, it's not impossible. On February 10th, a rider stepped off their sled and triggered a very large avalanche that failed near the ground on Lava Mountain. This avalanche was triggered where the overlying slab was thin making it possible for the rider to impact the underlying weak layer. Thin spots exist in rocky and wind affected terrain. Since deep slabs are extremely difficult to predict and carry high consequences, terrain choice remains the best way to avoid this problem. Manage this problem the same way you would manage weak layers in the middle of the snowpack (problem #2) by avoiding very steep, rocky, and heavily wind affected terrain.

    (2/11/2025)

    The crown of the recent unintentionally-triggered avalanche on the E face of Lava ~10,400'.

    Photo: Bridger-Teton Avalanche Center

Avalanche Discussion

Togwotee Pass has received around 6 inches of snow in the past 48 hours. Westerly winds have redistributed this snow and formed new slabs on exposed slopes. Another 3-6 inches of snow is expected today and will increase the size and distribution of these slabs as the day progresses. Monitor for rapidly changing conditions today. Increases in wind and snowfall will quickly increase the avalanche conditions and require a change in terrain selection. 

Weak layers of snow are buried at various depths around Togwotee Pass. Potential weak interfaces can be found from the January drought 2-4 feet down and November facets 5+ feet down. While there hasn’t been much activity reported on the weak layers in the middle of the snowpack recently, the very large avalanche on Lava Mountain is a good reminder that the snowpack structure remains poor overall and has the potential to create a large avalanche in isolated terrain.

Please consider submitting an observation HERE. Observations allow everyone to gain a better and more complete understanding of conditions. Thanks!

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