Bollettino valanghe

Sawtooth & Western Smoky Mtns

Sawtooth Avalanche Center
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Pericolo valanghe

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

In sintesi

Very dangerous avalanche conditions exist. Large natural avalanches are almost certain to occur in windy, alpine terrain. Numerous smaller avalanches are very likely in terrain more sheltered from the wind. You may not see any warning signs before triggering a much larger avalanche failing on weak layers deep in the snowpack. These will be big enough to bury you and snap trees. 

Problemi valanghivi

  • Wind Slabs

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

    Last night's storm delivered 6-13" of low-density snow to this zone, accompanied by moderate SW and W wind. Storm snow will not bond well where it lands on facets, crust + facets, slick crusts, and surface hoar. Due to these variable weak snow layers, expect to encounter a host of changing new snow problems. These will range from sensitive wind slabs at upper elevations to potentially touchy slabs and loose snow avalanches that fail readily in steep, sheltered terrain. 

    Look for obvious signs of instability, like small slides that released overnight or cracking and collapsing of the snowpack. Even smaller slides in more sheltered terrain can have big consequences if they push you into terrain traps like stands of trees or a creek bed. Importantly, any smaller natural or triggered avalanche has the potential to step down to a deeper weak layer, releasing one of the Persistent Slab avalanches described below.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–3

    You could trigger large avalanches, and some of them could be big enough to destroy houses. Multiple natural and human-triggered avalanches released in the southeastern portion of the zone during and shortly after storms in early February. In some areas, the snowpack is still adjusting to the load. Last night's snowfall may have pushed these slopes over the edge and left others on the brink of failure. 

    These slides will break 2-4 feet thick on weak layers of facets on shadier slopes and crust + facet combinations on sunnier slopes. Persistent slab avalanches can release in surprising ways. You can trigger them from flat or low-angle terrain long distances away from steep slopes, and they can break far above you. Before triggering an avalanche, you may or may not experience snowpack collapsing or other obvious signs of instability.

    The only surefire way to avoid this problem is to steer clear of steep slopes. Today, this includes the runouts of large avalanche paths. Natural avalanches in windier alpine terrain have the potential to trigger these slides as they cascade downhill.

    (2/10/2024) This very large avalanche failed naturally sometime between Friday night and Saturday morning. The crown spans 2,000 feet of terrain and the slide ran over 1,000 vertical feet. 

Avalanche Discussion

Last night's storm delivered a solid thump. This load may have been enough to push some slopes in the southeastern portions of the zone to the edge. These areas, including the mountains above Smiley Creek, were still adjusting to the load from the previous storm. The current set of storms is spreading precipitation more evenly throughout the western Smokys and near and west of the entirety of the Sawtooth Crest.

Snowfall is not likely to bond well to the very weak snow surfaces and facets that sit atop the very stout crust a foot or less below the surface. Storm snow problems, particularly freshly forming wind slabs, are a real concern. Any natural avalanches have the potential to run fast and far on slick crusts. Be alert to overhead hazards, and consider the consequences of being caught in an avalanche before committing to skiing or riding steep slopes.

Regioni coperte