Avalanche forecast

Tetons

Bridger-Teton Avalanche Center
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Avalanche danger

Alpine
4 · High
Treeline
4 · High
Below
2 · Moderate
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Out of date — this forecast expired 7 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Very dangerous avalanche conditions exist at the mid and upper elevations, and TRAVEL IN AVALANCHE TERRAIN IS NOT RECOMMENDED. Yesterday, numerous natural and human triggered avalanches were reported. The largest of these slides include a naturally released, three foot deep persistent slab on Lost Lifty Bowl to the south of the Jackson Hole Mountain Resort and another similar sized slide in Little Tuckermans on Teton Pass that was skier triggered. These very large slides are failing on weak, faceted snow near the base of the snowpack, and similar slides are very likely to be triggered today in terrain that held snow prior to Thanksgiving. Natural activity will also remain possible. Involvement in one of these slides will likely be fatal. Abundant new snow is very enticing, especially on weekends early in the season. Don’t fool yourself; this is not the time to be in, around or underneath any avalanche terrain where these persistent slabs reside. Recently developed wind slabs could also be triggered by backcountry travelers, and these smaller slides could step down and release a deeper persistent slab. At the lower elevations, pockets of wind slab could be triggered by backcountry travelers in very steep avalanche starting zones.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    2–3

    Weak, faceted snow persists near the base of the snowpack on slopes with an existing snowpack prior to Thanksgiving. Since December 8th, five and half inches of snow water equivalent has been added to these basal facets. In terrain were these persistent weak layers are present, skiers and riders are very likely to trigger slab avalanches with depths ranging from three to five feet. These avalanches could easily kill you or someone in your party. They are breaking high into lower angle terrain, running long distances and can also be remotely triggered.

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Wind slabs have formed in leeward terrain at all elevations. Slabs could be up to two feet deep at the mid and upper elevations and around a foot deep at the lower elevations. These recently developed slabs could be triggered by backcountry travelers in steep terrain.

Avalanche Discussion

Expect partially clearing skies overnight before cloud cover increases during the day on Sunday. A few isolated snow showers may be possible in the mountains, but any accumulations should be minimal. Overnight lows in the mountains will be near zero before rising into the single digits during the day. Northwesterly ridgetop winds will back to the west at 10 to 20 miles per hour.The general avalanche hazard at the mid and upper elevations is expected to be Considerable on Sunday. Persistent slabs will remain the primary threat. Skiers and riders could easily trigger these large to very large slabs in steep terrain that held snow prior to Thanksgiving. While the likelihood of triggering these slabs is decreasing, the consequences remain the same. These slabs are likely to be three to five feet deep in the Tetons and Southwest Trails area, and two to four feet deep in the Togwotee Pass forecast zone. If you are caught in one of these slab avalanches, a fatal outcome is likely. Recently developed surface slabs, with depths on one to two feet, could still be triggered by backcountry travelers in steep, wind-loaded terrain, and they have the potential to step down and release a deeper persistent slab. Expert snowpack evaluation and conservative terrain choices will be essential for safe travel in avalanche terrain. At the lower elevations, skiers and riders might be able to trigger an isolated pocket of soft slab in very steep avalanche starting zones. There, the general avalanche hazard is expected to be Low.

Regions covered