Avalanche forecast

Tetons

Bridger-Teton Avalanche Center
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Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Highlights

Watch for isolated areas of soft slab up to 18 inches deep in wind affected terrain at the upper elevations. These slides could be large enough to knock you off your feet and drag you into terrain traps such as trees or gullies. Any cracking or collapsing is a good indication that you found an area with a newly formed slab.

 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Light winds veering from the southwest to the north have formed isolated areas of soft slab 6-18” deep in upper elevation, leeward (NE-SE) starting zones. The distribution of these soft slabs are not widespread given the calm winds and low moisture content of the most recent snow. Yesterday, small (D1) slab avalanches were observed south of Jackson Hole Mountain Resort and west of Taylor Mountain. These slides are good examples of the isolated nature of the soft slabs that you may find. Watch for “thicker” or "upside down" feeling snow along upper elevation ridge lines. Any cracking or collapsing is a good indication that you found an area with a newly formed slab. Despite cold temperatures, direct sunshine today could make these slabs more sensitive to human triggers on steep, solar aspects. Monitor changes in snow conditions throughout the day and be wary of any terrain that has a significant slab as it is most likely sitting on a very weak surface.

    (1/7/2024)

    A small soft slab avalanche that was observed south of Jackson Hole Mountain Resort. This photo is a good example of terrain where these slabs may be found.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1–1.5

    While unlikely, avalanches involving weak snow buried 1-3 feet deep cannot be ruled out in steep, north facing terrain at the upper elevations. As of now, persistent slab avalanches are not of primary concern, however, this is likely to change as we add additional load to the snowpack.

Avalanche Discussion

The Tetons received anywhere from 8-16” of snow with .5-1” of snow water equivalent (SWE) in the past four days. Higher snow totals were observed on the west side of the range near Grand Targhee. For the most part, the new snow is lacking enough cohesion to create a significant slab. The exception would be in steep upper elevation terrain that is exposed to the wind. The new snow has fallen on a variety of weak surfaces formed during the December drought all of which do not bode well for bonding at the new/old interface. This interface will be of primary concern as significant snowfall and wind is expected by midweek.

Deeper in the snowpack is another widespread weak layer that formed in November. The last reported avalanche on this layer occurred on December 9th. Despite the lack of activity, tests in pits over the last month have shown this layer to have potential to become a problem again when it receives sufficient loading. The weight from the most recent storm has not been enough to reactivate this layer, but it will remain on the radar as a more impactful storm approaches. 

Isolated terrain features below 7,500' have accumulated enough snow to warrant a danger rating. In those locations, the avalanche danger is low.

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