Bollettino valanghe

Togwotee Pass

Bridger-Teton Avalanche Center
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Pericolo valanghe

Tue
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
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

Persistent weak layers buried 2-3 feet across all aspects and elevations make triggering a large avalanche possible. This high consequence, low probability scenario has lasted all season and requires careful terrain management and humility. Manage this problem by avoiding large avalanche paths and terrain traps that would result in serious consequences if caught in an avalanche.

Problemi valanghivi

  • Persistent Slabs

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

    Weak layers buried 2-3 feet deep continue to haunt the snowpack across all aspects and elevations. The main concern is the Feb 18th layer composed of crusts and facets. You can find unstable results in stability tests pretty much everywhere, with increased reactivity on southerly aspects with a weak facet/crust combination. The recent warming trend has not been sufficient enough to stabilize these layers. Triggering a large avalanche remains possible, especially on previously wind loaded terrain. Conservative terrain management is necessary during this low probability, high consequence avalanche problem. Avalanches failing on layers deeper than 3 feet are also possible on weak basal facets and depth hoar. Terrain with an increased likelihood of triggering a persistent slab include:

    • Shallow snowpack: Weaker buried layers of snow .
    • Wind-affected: Terrain where wind has formed firm, cohesive slabs of snow.
    • Steep: Over 35° slopes.

    Mocassin Basin 9500' E aspect

    Photo: Cory Beattie

Avalanche Discussion

Goodbye Sun, Hello Snow

Today we transition from one of the longer periods of clear and sunny conditions we’ve seen all winter back into the snow globe. This next series of storms does not favor Togwotee as much as the other zones. Snowfall is forecasted to trickle in with low totals, resulting in less avalanche concerns in regards to storm and wind slabs. The main concern is the dreaded persistent slab problem. The bottom line is that the poor snowpack structure is hard to ignore. The main concern is the Feb 18th layer that continues to show moderate to hard propagating test results. Perform a quick trench check on your machine or dig in the snow and you’ll feel these weak facets and poor crust combinations. Stay diligent in choosing terrain that matches this high consequence, low probability problem. Wind slabs are stubborn enough to be excluded from the problems. Understand that this does not mean they are not possible in very isolated terrain such as the most exposed ridglines and cliff features. 

Although totals remain low, snowfall will continue this week increasing the avalanche danger. The variety of snow surfaces created by strong solar radiation, winds, and cold nights has created poor interfaces for this new snow. Today is a good day to test the reactivity performing hand shear tests and finding small test slopes. Figure out the sensitivity and distribution of this interface across different aspects to set yourself up for the coming week of powder riding.

Regioni coperte