Bulletin d’avalanche

Snake River Range

Bridger-Teton Avalanche Center
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Danger d’avalanche

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

Points saillants

Heavy snow and strong winds have created very dangerous avalanche conditions. Slabs up to 2 feet in depth will be reactive to the weight of a skier or snowmobile. Natural avalanches are also likely in wind loaded mid/upper elevation terrain and low elevation terrain that experiences rain today. Traveling in, near, or under avalanche terrain is not recommended today.

The NWS has issued a Winter Storm Warning that is in effect until Monday at 11:00 am

Problèmes avalancheux

  • Wind Slabs

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

    New snow and wind over the past 48 hours has formed reactive slabs up to two feet deep in wind loaded terrain at the mid and upper elevations. Human triggered and natural avalanches are likely at all elevations/aspects. These slabs will increase in size and sensitivity with more precipitation, strong winds, and rising temperatures forecasted through the day. Storm snow instabilities may also be found in terrain sheltered from the wind where slabs will be 12-18” deep. 

    Assume that the snow will be unstable if travelling in the mountains today. Obvious signs of instability such as recent avalanches, shooting cracks, and collapsing indicate that the snow is ripe for avalanching. Given the potential for natural avalanches, it will be critical to consider the terrain that lies above you. This includes snowmobile trails that cross avalanche paths. Traveling in, near, or under avalanche terrain is not recommended today. 

    Rain on snow in low elevation terrain is possible today and will rapidly destabilize the snow surface. Monitor weather conditions closely as conditions warm throughout the day.

    (2/1/2025)

    A human triggered wind slab yesterday. Expect larger avalanches today.

  • Persistent Slabs

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

    Weak snow near the base of the snowpack lurks 2-5 feet below the surface. This avalanche problem is currently dormant in the vast majority of terrain. Exceptions may be found in very steep terrain with shallow overall snow depths.

Avalanche Discussion

The Snake River Range has received about a foot of snow containing over an inch of Snow Water Equivalent (SWE) in the past 48 hours. Yesterday, winds were averaging in the mid to upper 20s (mph). Speeds decreased overnight but are expected to ramp back up today.  Another foot of snow is possible by the evening. Throw a rain/snow line approaching 7,000’ into the mix today and the result is widespread dangerous avalanche conditions. 

A prolonged period of dry weather came to an end on Friday. Snow surfaces prior to this storm varied significantly, though none are conducive to stability. Crusts can be found on west-south-east aspects, weak faceted snow on west-north-east, stiff windboard on east-north-west in the upper elevations, and facets on many aspects in the lower elevations. Regardless of the underlying surface, expect to find instability in most terrain, especially as the day progresses. Areas experiencing enhanced loading from the wind will be even more prone to avalanching. Travel advice is simple today. Avoid being near or under avalanche terrain. Sheltered terrain that is no steeper than 30° is the safest option. 

If you see avalanche activity today, please consider submitting an observation HERE. Observations allow everyone to gain a better and more complete understanding of conditions. Thanks!

Régions couvertes