Bollettino valanghe

Togwotee Pass

Bridger-Teton Avalanche Center
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Pericolo valanghe

Fri
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
Senza grado
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In sintesi

Continued warm temperatures today will make wet slab avalanches possible on slopes facing the sun, especially around rock features. Look and feel for snow surfaces becoming wet and slushy as an indication of destabilizing snow in the upper portion of the snowpack. Seek cooler, shaded terrain when you encounter wet snow surfaces. 

Problemi valanghivi

  • Wet Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Increasing temperatures the last 6 days above freezing across all elevations has allowed water to penetrate through the snowpack increasing the possibility of large human and natural wet slab avalanches 1-2 feet deep. Avalanches on slopes facing the sun around rock features will be most probable, even as cloud cover develops today temperatures will remain warm. A natural wet slab avalanche two days ago near Breccia indicates that the snowpack is destabilizing. Avoid steep slopes if you encounter wet snow and are sinking significantly into a slushy snowpack. The snowpack is constantly changing during warming temperatures on a day to day basis. Therefore, multiple tracks on a slope are not an indicator of stability with this avalanche problem (see Bernie's Bowl avalanche for an example). 

    Wet Loose: Continued wet loose avalanches will be likely today. These avalanches start at a point and can entrain large amounts of snow and push into terrain traps. 

    Cornice Falls: Increased temperatures will also destabilize cornices. Give cornices a wide margin of safety and be careful along ridgelines as they can break further back than expected. Limit exposure under cornices where natural falls could occur. 

    Monitor snow surfaces throughout the day to avoid encountering any of the problems listed above. All these problems will be most likely in the afternoon. Seek snow that is colder and not as wet on shaded slopes.

    (3/20/2024)

    Natural wet slab avalanche that failed two days ago near Breccia on steep SE aspect at 9700' around rock features.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–2.5

    Triggering an avalanche remains possible on weak snow buried 2-4 feet deep below hard slabs. This weak, sugary snow exists across all aspects and elevations near the base of the snowpack. The last persistent slab avalanche occurred 3/16 in Upper Deception Creek. These avalanches are also difficult to predict, but areas where triggering is most probable include steep, rocky, and wind affected slopes on the north half of the compass. These slopes contain thin, shallow spots where riders can impact the weak layers more easily. Again, limit exposure underneath cornices. Cornice falls are the most likely way to trigger a very large persistent slab avalanche.

    (3/17/2024)

    This persistent slab avalanche was snowmobile-triggered on an E aspect at 9000' on 3/16. 

Avalanche Discussion

A natural avalanche was reported yesterday near Breccia that likely occurred 3/19. This avalanche failed where we would expect it, on a steep southerly aspect near rock features.This is a clear indication that water is penetrating through the snowpack and decreasing stability in the upper portion of the snowpack. Water continues to flow through the snowpack even though it may not feel as warm today with developing cloud cover. This can be deceiving as wet slab avalanches can continue even after peak warming. These avalanches are difficult to predict, even for professionals. Error on the side of caution today due to this uncertainty. Snow surfaces may warm quicker than previous days as temperatures were warmer last night than previous nights. Watch out for terrain highlighted in the Persistent Slab problem when seeking cooler snow surfaces on shaded terrain. Consistently cooler temperature will be required to stabilize the snowpack. Check the forecast in the coming days with weather changes as an active pattern and cooling temperatures impact the area.

 

Invitation to participate in the survey: 

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 risk communication. 

Link to the survey: 

https://caic2024.avalancheresearch.ca/en/

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