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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Highlights

New snow and strong winds are forming wind slabs on a variety of sliding surfaces including suncrusts, faceted snow and surface hoar. Backcountry riders and skiers could easily trigger these slabs in steep leeward terrain at the mid and upper elevations this morning. As heavy snowfall continues today the size and sensitivity of these slabs will increase and natural avalanches will become more likely, particularly at the high elevations where the winds are strongest. Weak snow near the base of the snowpack could also fail, resulting in large persistent slab avalanches. Larger triggers such as cornice drops, snowmachines, or a triggered wind slab may be necessary to trigger such an event. At lower elevations, soft slabs could be triggered in steep wind loaded avalanche starting zones. Cautious route finding and conservative decision making is essential today and travel in avalanche terrain is not recommended above 9000 feet this afternoon.

Avalanche problems

  • Wind Slabs

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

    Strong west to southwest winds continue to transport new and recent snow into avalanche starting zones. These slabs will be sensitive to backcountry travelers and will increase in size and sensitivity as the day progresses. Natural activity along ridge crests and peaks is expected this afternoon. Slab depths could reach two feet by the end of the day at the higher elevations and one foot at the lower elevations.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

    Above 8000 feet, weak snow lies near the base of the snowpack. This weakness is most likely to be found on northwest through northeast aspects although it does exist on other aspects at the higher elevations. New snow is stressing this layer, making it more susceptible to failure. If triggered, it would be difficult to survive one of these hard slab avalanches that could have crown depths to four feet.

Avalanche Discussion

Snowfall will become lighter after midnight and continue through the day. Additional accumulations of 4 to 8 inches are likely at the higher elevations with another 2 to 4 inches possible in the valleys. Westerly winds will continue with gusts from 35 to 45 miles per hour over the peaks on Thursday. Temperatures will be in the teens in the mountains and in the 20's in the valleys.Conditions are expected to be dangerous at the mid and upper elevations and in some steep active avalanche starting zones at the lower elevations. Westerly winds have formed new slab avalanches up to 30 inches in depth that can be triggered by humans and release naturally in steep wind loaded avalanche starting zones. Full depth avalanches can also be triggered by these surface slabs or by the weight of a person or a snowmachine. These dangerous slabs could be 3 to 5 feet deep. Expert terrain assessment and route finding skills will be essential for safe travel in avalanche terrain. The general avalanche hazard is expected to be considerable at the mid and upper elevations (7,500 to 10,500 feet) and moderate below an elevation of 7,500 feet.

Regions covered