Bollettino valanghe

Snake River Range

Bridger-Teton Avalanche Center
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Pericolo valanghe

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

In sintesi

Dangerous avalanche conditions exist. You are likely to trigger a large avalanche 1 to 3 feet thick on wind-loaded slopes above 35°. Avalanches could break into deeper weak layers to produce very large avalanches. If the sun pops out today, snow surfaces could destabilize very quickly, and loose snow avalanches could entrain large amounts of snow on steep, sunny slopes. Watch for shooting cracks in wind-affected snow and also warming snow surfaces and roller balls if the sun comes out. Ride lower-angle terrain and give steep slopes above you some room.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Very Likely
    Dimensione
    1–2.5

    Twenty-four inches of snow in the last 48 hours in the Snake River Range, and moderate westerly winds have formed slabs on lee aspects and in cross-loaded terrain features up to 3 feet thick. This problem exists mainly above 7500 feet. Look for drifts and thick pillows where you could see obvious signs like shooting cracks and collapsing. With almost 4 feet of snow in the Snakes this week, while unlikely, wind slabs could break deeper than 3 feet in isolated areas around steep, rocky, unsupported slopes and convexities where wind has deposited very large amounts of snow. Steep slopes below 7500 feet could have isolated pockets of wind slabs in very exposed areas or behave more like storm slabs in less exposed areas. Ride sheltered terrain to avoid this problem and give terrain traps plenty of room.

    The sun could make an appearance today and quickly destabilize snow surfaces on steep sunny slopes, especially below 9000’. It will not take long to see small, wet loose avalanches with all of the new snow that we have. These avalanches will start around cliffs and steep rollovers and could entrain large amounts of snow. If you see roller balls or encounter moist or wet snow surfaces, move to shadier terrain. Tree bombs will be a threat with warming temps and any sunshine.

    (2/17/2025)

    Example of recent wind slab in southern Tetons. 

  • Persistent Slabs

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

    It remains possible to trigger a very large avalanche up to 5 feet deep at middle and upper elevations. We continue to track the facet and crust layers that were buried on 2/6, and while we have not seen much activity there, pit tests in adjacent forecast zones continue to show the poor structure, and some ECTs have propagated at this crust/facet interface. A wind slab avalanche could be the large trigger needed to step down to this layer, or you might just get unlucky and find that thin spot where you can impact this layer. You won’t see clues (cracking and collapsing) until you trigger an avalanche on this layer. There’s not much you can do to manage this problem except give yourself a safety margin around very steep slopes while the snowpack adjusts to the huge load we received over the last several days.

    (2/11/2025)

    This layer of concern now has another 3 feet of snow loading it...

    Photo: Bridger-Teton Avalanche Center

Avalanche Discussion

Be patient and conservative out there today. We have two overlapping avalanche problems that could both produce very large avalanches. Visibility has been poor this week and we just don’t have a great idea yet of the big-picture results of 4 feet of snow in several days. A lack of big avalanche observations can produce a sense of stability - maybe it’s false and maybe it’s not - we just don’t know yet. But we do know better than to go center-punching on the first day of good visibility following the biggest storm of the year. Dig around, take pictures, and let us know what you find out there - thanks!

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