Bollettino valanghe

Togwotee Pass

Bridger-Teton Avalanche Center
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Pericolo valanghe

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

In sintesi

Triggering a large avalanche is possible today. This danger exists in steep, wind loaded terrain where weak, sugary snow sits at the base of the snowpack. These avalanches could be remotely triggered from a distance.  Ride low angle, sheltered terrain.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    1

    Snow and wind from the weekend formed wind slabs on lee terrain along ridges and exposed terrain above 9500’. These slabs will be located on NW-N-NE-E-SE and are 1’ to 2’ thick. As you travel, feel for denser snow in these locations and look for pillows that will be more prone to cracking and collapsing. This problem can also be found below ridges and around terrain features that have been cross-loaded by the wind. 

    It is unlikely that you will trigger a wind slab but remember that these slabs are adding stress to the persistent slab problem.  Seek out sheltered and low angle terrain.

    (12/9/2023)

    Natural D2 soft slab avalanche 9400' NE aspect

    Photo: Alex Drinkard

  • Persistent Slabs

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

    A cold and dry November left a weak layer of sugary snow that continues to be a problem. The slab that lies over this weak snow could be 1-3’ thick (thicker where it has been wind loaded). Steep, rocky, northerly terrain will be the easiest location to find this problem but is possible wherever you find buried facets.

    Continue to travel on slopes less than 30 degrees that are not connected to steeper slopes above. Take the time to investigate what’s beneath you. Watch for shooting cracks and listen for collapsing. Dig a hand pit, probe with your ski pole, or look at what your snowmachine has trenched through. If you find sugary snow you have found the weak layer. Hard slabs formed from December storms can be unpredictable, fail remotely from below or above and propagate farther than you might expect. There may or may not be signs of instability such as cracking or collapsing before an avalanche is triggered. Keep an eye out for terrain traps as you travel and remember that even a small slope above a trap can bury you quickly. Tracks on a slope do not guarantee stability.

    Avalanche failed on old facets near the ground. 

    Photo: Drinkard

Avalanche Discussion

Our setup right now is simple. We have a cohesive slab of snow from the December storms that is sitting on a weak layer of facets (weak, sugary snow). This slab has seen a few days of relatively warm temperatures, including yesterday in the mid 30s F around Togwotee. These temperatures have settled the slab into a more firm and cohesive layer. In terrain around ridges and exposed features, the slab is thicker from wind redistribution. The lower elevation approaches are still relatively shallow so watch out for hidden obstacles!

It will take time and more snow for this problem to resolve. Be patient and enjoy the low angle, sheltered terrain and please continue to send us observations - they are incredibly helpful!

Regioni coperte