Bollettino valanghe

Togwotee Pass

Bridger-Teton Avalanche Center
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Pericolo valanghe

Wed
Alta quota
2 · Moderato
Limite del bosco
3 · Marcato
Sotto il limite
Senza grado
Non aggiornato — questo bollettino è scaduto 3 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

The avalanche danger will rise today as temerpatures warm and solar input increases. You are most likely to trigger an avalanche in steep terrain and the chance of triggering a hard slab avalanche will increase throughout the day.  Use conservastive decisions in steep terrain and watch for changing snow conditions.  Small wet natural avalanches will happen on warm, sunny slopes. Consequences remain high and even small avalanches above gullies and creek beds can bury you.

Problemi valanghivi

  • Persistent Slabs

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

    Weak snow lies 1-3 feet below the surface above 9000 feet. Below that elevation this weak layer is only about one foot down. This persistent slab problem exists on all aspects at upper elevations and mostly northerly aspects at mid elevations. This distribution means that you’re most likely to trigger an avalanche in steep shady terrain, especially around wind affected terrain, convexities or rocky, shallow areas in the snowpack. Due to the widespread nature of the weak layer, it will be possible to remotely trigger a slab avalanche and the resulting slide could propagate long distances. As you’re riding, watch out for steep slopes above you and give terrain traps plenty of room. Even small avalanches triggered above gullies and creek beds can bury you and have high consequences.

    The danger level will increase throughout the day as temperatures warm and solar input increases. Expect the snowpack to be more sensitive in the afternoon especially on mid elevation southerly aspects. Monitor the snow surface for wet, saturated snow and increased natural activity, signs of increasing avalanche hazard.

    (1/20/2024)

    This avalanche occured sometime between 4pm on Jan 19 and 8am on Jan 20th. SS-N-R4-D2-O. East aspect at 9,400 feet.

    Photo: Matthew Tousignant

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–1.5

    Warming temperatures and sunshine will increase the avalanche danger throughout the day and could produce natural wet loose avalanches on steep sunny slopes, especially around rocks and cliffy areas. These avalanches will most likely be small but could be consequential if you are pushed into terrain traps or trees. It is possible that wet loose avalanches could step down and trigger a deeper instability if enough snow is entrained to trigger the persistent weak layer. If you step off your sled on a sunny slope and sink to your shin in wet snow, it’s time to move to a colder, shadier aspect and stay out from underneath steep slopes.

    (12/28/2023)

    Natural wet loose avalanche activity in the upper elevations of the Tetons could pose a hazard in the wrong terrain.

    Photo: Gabrielle Antonioli

Avalanche Discussion

It’s easy for me to try and overthink the current situation, especially given changing conditions and shifting danger with increased temperature and sun. Here are a few points to consider as you are riding to help distill it all down.

  • The persistent slab is our #1 concern. It is widespread and most likely on steep shady slopes.
  • As temperatures rise and the sun comes out, the persistent slab remains our #1 concern. Rising temperatures and increased solar input will increase danger (sensitivity) on steep sunny slopes.
  • If the weather forecast holds and it does get warm and sunny, we add in the wet loose avalanche problem. Think small avalanches originating from steep rocky areas. As the day progresses, pay attention to increased warming because these slides might start to entrain enough snow to push you around.

As always, a bigger safety margin helps with risk management. We can increase our margins by;

  1. Avoiding steep connected slopes, convexities, and thin areas in the snowpack.
  2. Using safe travel techniques including traveling one at a time in suspect terrain and using safe zones to regroup.
  3. Avoiding terrain traps with steep slopes above.
  4. Stay off of slopes where snow has become wet, slushy and isothermal. 

Regioni coperte