Avalanche forecast

Salt River and Wyoming Ranges

Bridger-Teton Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 3 years ago.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

Highlights

While unlikely, the chance exists for backcountry travelers to trigger a large avalanche that fails on weak snow in the lower half of the snowpack. Shaded upper elevation terrain that is steep, rocky, and unsupported could produce a destructive avalanche.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1.5–2.5

    Slabs of cohesive snow 1-3 feet thick overlay weak, faceted snow that formed during a dry period in November. While unlikely, the potential exists to trigger an avalanche at this interface on northwest through northeast aspects above 8,500’. Collapsing the weak layer in a shallow portion of the snowpack, especially in very steep and unsupported terrain, is the best way to trigger one of these avalanches. Keep in mind that a slope can be ridden several times before a particularly thin, weak spot is impacted. 

    Slopes that hold weak snow from November vary between the Salt River, Wyoming, and Snake River Ranges. As a result, terrain where the persistent slab problem can be found will differ slightly from one range to another. Digging into the snowpack is the only way to know for sure if this problem exists. Trenching your snowmobile or probing with a pole to feel for hardness changes (hard snow over soft snow) are also easy ways to identify this layer. Remember that a slope 50 yards away from the one you just dug on will likely hold a different snowpack. Before entering steep consequential terrain, take a minute to think about the snow structure beneath your feet and the consequences of being caught in an avalanche.

    Be on the lookout for loose snow sluffs in upper elevation terrain that received higher amounts of snow two days ago (~6” in the Salt Rivers). Small point releases may become more active as the day progresses due to sunny conditions.

    A good example of terrain that is "steep and unsupported". East facing terrain near Smith Fork.

    Photo: Frank Carus

Avalanche Discussion

Two weeks without a significant loading event has given the weak snow in the lower half of the snowpack time to adjust to the load from the early December storms. Consequently, it has become difficult, but not impossible, to impact the weak layers in the lower half of the snowpack. Shallow, rocky areas near cliff bands are still great places to find a trigger point. Stability test results from the Salt River Range yesterday still show potential for propagation in high north facing terrain. If you choose to step out into steeper terrain, be cautious of terrain traps such as creeks and gullies. Even a small avalanche in a terrain trap can carry severe consequences. Although we are trending towards low avalanche hazard, it is important to practice safe backcountry travel habits. This means exposing only one person to avalanche terrain at a time and stopping in appropriate safe zones. Don’t be fooled into thinking that the current persistent slab problem involving the November drought layer will fade away quietly. The next significant loading event will likely bring it back to the forefront of our concerns.

Clear and cold conditions during the second half of December helped to form another layer of weak snow. Facets and surface hoar have been observed on terrain on the north half of the compass. Crusts can be found on steep south facing and low elevation terrain. This layer is now covered with a small amount of new snow from two days ago. It will be important to keep track of this December drought layer as it gets buried by any new snow. Finally, snow coverage at the lower and middle elevations remains thin in the Greys River zone. This makes access to the upper elevations challenging. In addition, many obstacles are lurking just beneath the snow surface.

Regions covered