Avalanche forecast

Snake River Range

Bridger-Teton Avalanche Center
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Avalanche danger

Thu
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
1 · Low
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Out of date — this forecast expired 8 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

Strong wind combined with heavy snow falling on a poor bonding interface will form dangerous avalanche conditions in the middle and upper elevations by the afternoon. Natural avalanches are possible and human triggered avalanches are very likely as the size of avalanches increases throughout the day. Avoid being on or beneath steep, wind loaded slopes.

Avalanche problems

  • Wind Slabs

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

    Snowfall rates of 1-2 inches per hour are expected today with up to a foot of new snow by the afternoon. Slabs up to 2 feet deep will be formed by strong SW wind 20-30 mph in wind loaded terrain. Expect avalanches to run far and wide, as the new dense snow falls on a widespread rain crust.  Triggering an avalanche will be likely even in sheltered terrain above 7,500’, but largest and most dangerous where it has been wind loaded on open and exposed slopes. 

  • Persistent Slabs

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

    Weak layers formed in November are buried 2-4 feet deep below hard slabs. These weak layers are most pronounced on northerly, shaded aspects. New snow today will begin to add stress to these weak layers. Although the likelihood is still low, it will be possible to trigger a large, destructive avalanche in isolated terrain that is very steep, rocky, and wind affected. On those slopes, riders can impact the weak layers easier where the overlying slab is shallow and sensitive. Triggering a wind slab is another way to initiate a larger persistent slab avalanche.

    (12/11/2025)

    Large natural avalanche that occurred at the end of the storm on Dec 10th in the nearby Teton Range.  Slab formed by wind loading looks to have failed on the persitent weak layer buried in early November. 

Avalanche Discussion

Return of Winter

After a lull of warm, dry, spring-like weather we are back to winter. A widespread crust (also known as a poor bonding interface) was formed by rime and rain Dec 9-10th and can be found up to 10,000’ across all aspects in the Tetons and Snake River Range. This Winter Storm Warning will produce rates of heavy snowfall and over 1” of snow water equivalent by the end of the day. Rapid loading combined with a poor bonding interface creates avalanches. Simple as that. The main take-away today is that avalanche danger will exponentially increase as the snow stacks up. The good news is that temperatures are forecasted to decrease through the storm, which should help the new snow bond over time. Strong winds will not help, however. Perform quick hand shear tests and watch how the new snow behaves throughout the day. Natural avalanche activity on wind loaded slopes will be possible if high end snow totals pan out. For this reason, add in larger margins of safety to your travel plans. 

This winter can be characterized as abnormally warm, dry and just plain weird. Even with difficult access to the majority of backcountry terrain, we have already experienced a significant avalanche cycle on the weak, faceted snow formed in November. These weak layers adjusted to the load during the lull of dry weather as the overlying slab gained strength. As we start to load and add stress to these weak layers, we can expect the possibility of triggering to increase. Keep these weak layers in mind during times of rapid loading of snow and wind. 

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