Avalanche forecast

Salt River and Wyoming Ranges

Bridger-Teton Avalanche Center
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Avalanche danger

Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

While the avalanche hazard has slowly decreased, it is still possible for a person to trigger a very large slab avalanche, and if this occurs, the consequences would likely be fatal. In addition to this high consequence problem, backcountry travelers could trigger wet slides as the day warms, and if triggered, wet slides could initiate the failure of deeper slab avalanches. Above freezing temperatures and direct sunlight, will be the main contributing factor in decreasing the snowpack’s stability today. Yesterday in the afternoon, snowmobilers triggered wet slides in both the Togwotee Pass and Grey’s River forecast areas. Today, the temperatures at the mid-elevations are starting out warmer than the previous days this week, and depending on the cloud cover, the hazard may quickly increase between the elevations of 7,500 to 8,500 feet. The warming temperatures will also increase the potential for triggering avalanches at the lower and upper elevations and weaken cornices. As the snow surfaces become damp, the stability can quickly change to unstable, and being on or below steep slopes at all elevations should be avoided. Backcountry travelers should use careful evaluation of the snowpack and terrain to travel safely through the mountains.

Avalanche problems

  • Deep Persistent Slabs

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

    Avalanches involving old snow layers could be triggered with depths of 4 to 8 feet above 8,000 feet and to 2 to 4 feet below that elevation. These slabs will be more sensitive as temperatures warm above freezing. Yesterday, in the Palisades area of the Snake River Range on a steep slope in the afternoon, a snowmobile triggered a wet slab that failed on weak faceted snow at the base of the snowpack. In areas where the snowpack saw avalanche activity before the warm-up, wet slides could be easily triggered on buried weak layers during the warmest periods of the day. There was also an observation in the Wyoming Range by Gunsight Notch, where a cornice failure triggered a persistent slab several feet in depth. Backcountry travelers could encounter similar hazards today.

Avalanche Discussion

( Discussion is generated from the previous day's afternoon forecast. )Overnight, temperatures are expected to drop into the teens in the mountains and single digits in the valleys. The day will start with clear skies. Then, as a Pacific disturbance passes over the region, cloud cover will increase, and there is a slight chance for light precipitation. The high temperatures are expected to be in the upper 30s in the mountains and 40s in the valleys. Southerly to southwesterly ridgetop winds will be 10 to 20 in the morning and increase in the afternoon. In the Grey’s River and Togwotee Pass forecast areas, deep persistent slab avalanches, up to 8 feet deep, still pose a threat. While the avalanche hazard in these forecast areas has slowly decreased, it is still possible for a person to trigger a very large slab avalanche, and if this occurs, the consequences would likely be fatal. In the Teton forecast area, large slab avalanches have become unlikely, although as the day warms the potential for triggering slab avalanches up to 4 feet deep will be possible. The avalanche hazard is expected to be Moderate in all three forecast areas tomorrow. Daily warming will increase the potential of triggering an avalanche, weaken cornices, and could cause wet slides. Backcountry travelers should use careful evaluation of the snowpack and terrain to travel safely through the mountains.

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