Bollettino valanghe

Stevens Pass

Northwest Avalanche Center
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Pericolo valanghe

Thu
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
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In sintesi

On Wednesday, lots of new snow and wind will make it easy to trigger avalanches on a variety of steep slopes.  Use small test slopes and quick snowpack tests to assess the new snow. Avoid steep slopes where the wind has deposited snow, and if you see fresh avalanches or tests that fail suddenly, stick to slopes less than 35 degrees even in wind-sheltered terrain.

Problemi valanghivi

  • Storm Slabs

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

    Heavy snow, strong winds, and slight warming are a recipe for dangerous avalanche conditions. In sheltered terrain, you could easily trigger storm slab avalanches. The most dangerous terrain will be wind-loaded slopes near ridgelines and exposed locations, where avalanches will be larger and easier to trigger. Wind speeds will be strong overnight, though you may not see blowing snow during the day. Avoid steep terrain and convex rollovers, especially in wind-affected areas. Instead, stick to low-angle forested slopes as your safest option. At upper elevations and along steep ridgelines, natural avalanches could occur, so don't linger in the runouts of large overhead avalanche paths. 

    (12/24/2024)

    An example of steep terrain where you are likely to trigger an avalanche, as in this photo. 

    Photo: Katie Warren

Avalanche Discussion

Wednesday will be another stormy day. Both wind and snowfall will be most intense on Tuesday night, then taper during the day. While conditions will remain dangerous, the danger will not increase as rapidly as on Tuesday. Temperatures will remain cold with low snow levels. Storm totals could exceed 2.5 feet by Wednesday evening, especially as low-density snow accumulates with cooling temperatures. 

On Tuesday, observers reported triggering avalanches in the new snow on both wind-sheltered and leeward slopes. They reported wind drifts up to 2 feet deep at middle elevations. Weather stations reported about 12" of new snow by the end of the day. 

We don't have many details about the upper elevation snowpack. There's no doubt that recent wind slabs will be quite deep, and cornices could be large and easy to trigger. Triggered avalanches could be even larger than elsewhere. If you make it above 6,000ft, take time to investigate the top 3 feet of the snowpack. If you find strong over weak layering, stick to low-angle terrain and avoid being under steep slopes.

There are a few crusts in the snowpack that serve as good markers, though none of them are a problem for avalanches. You can find the January 3rd melt-freeze crust about 2-3.5 feet below the surface, and it's well-bonded to the layer immediately above. About  1 foot below the January 3rd crust is a thin December 24th crust, which can be found up to 5500ft. A stout crust from December 18th, just below the middle of the snowpack. 

Regioni coperte