Lawinenlagebericht

Togwotee Pass

Bridger-Teton Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Sun
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
Keine Stufe
Open full map
Veraltet — dieser Lagebericht ist 2 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

The weather that is moving through our region is bringing new snow and wind that will actively build slabs on the surface. Avalanches are expected to become more likely as the storm continues throughout the weekend. Watch for changing/intensifying weather, use caution around terrain that may be recently loaded, and remember that large persistent slab avalanches remain a possibility.

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    A storm has moved into our region and is forecasted to bring snowfall and significant winds throughout the day. Active wind slab creation is expected. The new snow is falling on snow surfaces that have been shaped by recent sun and warm weather. In other words, crusts. The storm snow will struggle to bond with the harder old surfaces. Winds will intensify as the day progresses and may transport snow to unexpected spots. Wind slab hazards are expected below ridges and on leeward slopes. Additionally they can form mid slope from cross-loading or surprise you if swirling weather deposits snow somewhere unexpected. Monitor for pillowy snow surfaces and cracking. Keep an eye on where the wind is moving snow. This hazard may exist at mid elevations.

    This image shows how wind can transport snow. A southwest aspect has been stripped and the adjacent slope loaded. In this case, a wind slab would be expected at ridgetop as well as several hundred feet below the summit.

    Photo: Travis Baldwin

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1.5–2.5

    Triggering a persistent slab avalanche is possible on weak snow buried 2-4 feet deep. The weak, sugary snow exists across all elevations and aspects except middle-elevation southerlies. The most probable areas to trigger a persistent slab avalanche include steep, rocky, and wind-affected slopes on the north half of the compass. These areas contain thin, shallow spots where riders can more easily impact weak layers. Shallower snow is also found east of the continental divide and south towards the Gros Ventre Range. Previous tracks on a slope are not an indicator of stability. Use caution in steep terrain and give yourself a wide margin of error on slopes with high consequences or near terrain traps. Move to low-angle terrain to avoid this problem. 

    The last known persistent slab avalanche occurred on 3/16 in Upper Deception Creek. On 3/19, a wet slab avalanche failing on these persistent weak layers occurred on Breccia. More avalanches such as these will likely occur today, and many problems may span the border between a wet slab and a persistent slab problem. However, both will be equally destructive avalanche types.

    This pit from late March shows that weak snow still characterizes most of the Togwotee snowpack, especially the base. These problem layers remain preserved and mean the snowpack has poor structure.

    Photo: Travis Baldwin

Avalanche Discussion

Spring weather has brought another swing to our avalanche problem list. Cooler temperatures and an incoming storm have removed wet slab as a concern and brought back wind slab. Conditions change fast this time of year and it is important to be able to analyze how each day’s weather pattern impacts stability. The new snow is arriving with a lot of wind and is unlikely to bond well to old snow surfaces. Snowfall during the day today should be modest, with rates intensifying tonight. However, be aware that the wind will shape how the new snow is distributed and wind slabs will probably be easy to trigger once formed. 

Much of the Togwotee snowpack continues to be characterized by weak snow at the base. This problem is most likely to be triggered in thin, rocky spots where the snowpack is shallowest. There is always a potential for a wind slab to step down and trigger a larger, more destructive slide when you have this type of snowpack. Monitor the incoming storm, stay off slopes that have signs of loading, and choose terrain carefully.

Help us improve avalanche forecasts! CLICK HERE to take an avalanche forecast survey and be entered into a prize drawing. The Colorado Avalanche Information Center, the Avalanche Research Program at Simon Fraser University, and the U.S. National Science Foundation National Center for Atmospheric Research are researching how skiers, snowmobilers, snowshoers, ice climbers, and anyone else who travels in the backcountry interpret avalanche forecast information. Part of this research includes a specific survey to better understand how useful avalanche forecast information is for trip planning. 

Completing this survey will take approximately 20 minutes. Thank you for sharing your feedback to help us improve avalanche hazard communication. 

Abgedeckte Regionen