Bulletin d’avalanche

Snake River Range

Bridger-Teton Avalanche Center
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Danger d’avalanche

Fri
Alpin
2 · Modéré
Limite forestière
2 · Modéré
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

Today, it remains possible to trigger a large avalanche 1 to 3 feet thick on wind-loaded slopes above 35°. These avalanches could be large enough to bury, injure, or kill you. Watch for shooting cracks in wind-affected snow. Slopes around cliffs, rocky features, and steep gullies often harbor wind-loaded snow. Ride sheltered, lower-angle terrain to avoid this problem.

Problèmes avalancheux

  • Wind Slabs

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

    Twenty-six inches of snow in the last three days in the Snake River Range and moderate westerly winds have formed slabs on lee aspects and in cross-loaded terrain features 1 to 2  feet thick. This problem exists mainly above 8000 feet and is becoming more difficult to find. Look for drifts and thick pillows where you could see obvious signs like shooting cracks and collapsing. There is a chance that wind slabs could break deeper in isolated areas around steep, rocky, unsupported slopes and convexities.  Wind often deposits more snow around these terrain features. Ride sheltered terrain to avoid this problem and give terrain traps plenty of room.

    (2/17/2025)

    Example of recent wind slab in southern Tetons. 

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    1.5–2.5

    It is becoming unlikely that you will trigger a very large avalanche that fails on deeper weak layers buried up to 3 feet. Rapid settlement and increasing temperatures create some uncertainty on the reactivity of the new slab sitting on these weak layers. This problem exists at middle and upper elevations, where weak snow was buried during the first week of February. This layer can be found in pits and can still show propagation but is becoming deeper and less likely to be impacted. While the likelihood is decreasing, the consequence of triggering a very large avalanche on this layer could be deadly. There’s not much you can do to manage this problem except give yourself a safety margin around very steep slopes while the snowpack continues to adjust to the big load we received over the last week.

    (2/11/2025)

    This layer of concern now has another 3 feet of snow loading it...

    Photo: Bridger-Teton Avalanche Center

Avalanche Discussion

Many avalanche accidents occur during Moderate danger - especially the day after dropping the danger level from Considerable. 

We got some visibility yesterday, and several large avalanches were observed in the adjacent Teton zone, mostly above 9000 feet. There were also smaller naturals observed in wind-loaded areas at middle elevations. Those avalanches most likely failed during peak loading earlier in the week. It’s a good reminder that there are buried weak layers even though evidence is lacking in many of the more commonly traveled areas. Patience remains important as the snowpack continues to adjust to the week’s storm. The Snakes received up to 47” of snow and 4” of SWE since the February 14th. We remain in a low-likelihood and high-consequence situation with good riding quality (above the zipper crust that formed yesterday up to 8k), tempting us into more avalanche terrain. Consider the consequence of a large avalanche if the slope you want to ride avalanches. Evaluate the snow and terrain carefully. Dig around, take pictures, and let us know what you find out there - thanks!

Régions couvertes