Lawinenlagebericht

Snake River Range

Bridger-Teton Avalanche Center
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Lawinengefahr

Fri
Hochgebirge
3 · Erheblich
Waldgrenze
3 · Erheblich
Unterhalb
2 · Mässig
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Kernpunkte

Dangerous avalanche conditions exist. Triggering a very large avalanche 2-3 feet deep is possible in steep terrain above 8500’ that could travel far across the slope or above you. Warning signs like collapsing and crackling may not be evident until it’s too late and you trigger an avalanche.  Be conservative with decision-making around slopes steeper than 30°.

Lawinenprobleme

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1.5–3

    Triggering a very large avalanche big enough to bury you is possible on steep, rocky, convex, or wind-loaded slopes over 35° above 8500’. 2-3 feet of snow that fell this week sits on a variety of weak layers that were covered on January 31st. This 1/31 weak layer is widespread and consists of facets and crusts. Avalanches failing on the 1/31 interface could travel far distances (including above you) due to the widespread distribution and continuous nature of the overlying slab. Managing this problem will be difficult because signs of instability, such as collapsing, cracking, or recent avalanches, may not be present. Many slopes may appear stable due to the nature of the hard slab. Multiple tracks on a slope are not necessarily an indication that it is safe – it might take one more rider to find the trigger point. Choose conservative and lower-angle terrain to manage the dangerous high-consequence avalanche conditions. 

    Weak snow near the base of the snowpack lurks 3-6 feet below the surface. The snowpack is continuing to adjust from the weight of the recent storm. Avalanches involving these layers could occur with a significant trigger, such as a large avalanche triggered at the 1/31 interface.

    (2/3/2025)

    A large skier triggered avalanche on a NE facing slope at 9,400' south of JHMR. It failed just above the new/old interface that was buried on 1/31. Seven skiers were caught and carried. All members of the party survived the incident.

    Photo: Bridger-Teton Avalanche Center

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1–1.5

    Triggering a small wind slab less than a foot thick is likely at middle and upper elevations on lee aspects. Several inches of snow fell in the Snake River Range yesterday. Periods of strong SW winds (observed on Baird) moved snow to lee aspects. Watch for shooting cracks, collapsing, and drifting around cliffs, gullies, and areas exposed to the wind. While these slabs will be small, they could knock you off your feet and have the potential to step down to the 1/31 interface. Ride in sheltered terrain to avoid this problem.

    (2/4/2025)

    A natural wind slab avalanche from the SE ridge of Smoky Hollow Peak. NE aspect 8800'. 

    Photo: Bridger-Teton Avalanche Center

Avalanche Discussion

The snowpack has gone through a lot of rapid change since Jan 31st causing unstable snow in the top portion of the snowpack. Prior to the recent storms, cold and dry conditions formed widespread weak layers of facets across many aspects and elevations. These weak layers are now buried by dense slabs and capable of producing destructive avalanches. Over 3” of snow water equivalent (weight of the snow) fell onto this weak interface – that’s a lot of weight, and the snowpack is still adjusting.

Above-freezing temperatures came to an end yesterday. Terrain up 8000’ where water was flowing through the snow will be frozen – expect firm conditions and travel accordingly.

As we give the snowpack time to adjust, be conservative around avalanche terrain. It’s a good time to go back to an assessment mindset and start digging in the snow to see where the latest persistent weak layer (1/31) exists and if it is more likely to propagate a fracture (ECT and PST tests). 

Please continue to send in your observations, thanks!

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