Avalanche forecast

Tetons

Bridger-Teton Avalanche Center
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Avalanche danger

Alpine
4 · High
Treeline
3 · Considerable
Below
2 · Moderate
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Out of date — this forecast expired 11 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Close to 18 inches of light density snow has fallen in the past 24 hours. Overnight, westerly ridgetop winds increased to 20 to 30 miles per hour and temperatures have warmed a few degrees. This combination has created an upside-down snowpack and very dangerous avalanche conditions. Backcountry travelers are very likely to trigger wind slabs in steep, wind-loaded terrain. In more sheltered areas, loose snow sluffs are also possible. These slides also have the potential to step down to faceted snow near the base of the snowpack above 7,500 feet. TRAVEL IN AVALANCHE TERRAIN IS NOT RECOMMENDED ABOVE 9,000 FEET. A conservative approach to both terrain selection and decision making will be essential for safe travel in avalanche terrain below 9,000 feet.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    1–2

    Skiers and riders could easily trigger new and recently developed soft wind slabs on all aspects and elevations. At the higher elevations, these slabs could have depths of one to three feet and fail on old hard surfaces or density breaks within the recent snowfall. At the lower elevations, they lie upon faceted snow and could release up to 18 inches deep. Beware of steep terrain with obvious areas of wind loading. Several of these wind slabs have been reported in recent days on a variety of aspects and elevations.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    Above 7,500 feet, hard slabs with depths to six feet lie upon persistent weak layers of faceted snow. Since Wednesday night, two and half to three inches of snow water equivalent has been added to the snowpack. Large triggers, such as groups of people, may be needed to trigger one of these slides. The release of a wind slab could also step down to these basal facets. If triggered, these slabs will carry high consequences.

Avalanche Discussion

After a brief lull, the next in a series of Pacific weather systems will bring cloud cover and snowfall to the region beginning tonight and continuing on Monday. Overnight lows in the mountains will be in the low to mid-teens before rising into the mid-20s during the day. Southwesterly to westerly ridgetop winds will increase to 20 to 30 miles per hour by early morning.The general avalanche hazard is expected to be Considerable on Monday and will increase during the day as new snow accumulates. Wind slabs, with depths of one to three feet, are likely to be triggered by backcountry travelers in steep, wind-loaded avalanche terrain. Deep persistent slab avalanches in the Tetons and Greys River area and persistent slab avalanches in Togwotee Pass forecast zone will remain possible. If triggered, these slabs will result in high consequences and could be up to six feet deep in the Tetons. In the Togwotee Pass and Greys River areas, slab depths could reach four and five feet, respectively. Large triggers, such as groups of people, may be needed to initiate one of these slides, particularly in the Tetons where the persistent weak layers are the deepest and most difficult to impact. The release of a wind slab could also step down to these basal facets. A conservative approach to both terrain selection and decision making will be essential for safe travel on Monday.

Regions covered