Bollettino valanghe

East Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

If you use the nice weather to get into higher elevations and find cold, dry snow, consider choosing lower-angle routes and avoiding steep wind-drifted slopes. You could trigger an avalanche where recent snow accumulated over weak layers, and slides may propagate farther than expected. Sunday's warm temperatures and a cool night will likely form a crust on surfaces, limiting avalanche danger at lower elevations. 

Problemi valanghivi

  • Storm Slabs

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

    Where you find cold, dry snow at upper elevations that escaped Sunday's warmup, you could trigger avalanches on steep terrain. Recent snow accumulated over surface hoar, slick crusts, and weak faceted layers. This complex and variable snowpack means that slopes close in proximity could have significantly different avalanche conditions. Make frequent assessments of the new snow using representative, small test slopes, and quick hand pits. If you find the snow slides easily, back off steep terrain objectives and choose lower-angle slopes to avoid triggering avalanches. In areas below corniced ridgelines and the base of cliffs, winds drifted snow deeper, and you could trigger a much larger wind slab. Textured surfaces and pillowlike drifts are good visual clues to identify likely wind slab locations. Shooting cracks, collapsing, and recent slab avalanches are clear signs that you should avoid steep, exposed terrain.

    (1/3/2025)

    A human-triggered avalanche near White Pass. This slide broke widely and was triggered from further back on the ridge. [N 5500']

Avalanche Discussion

After a very warm day on Sunday, expect cool overnight temperatures with some clear skies to form crusts at mid and lower elevations in many areas throughout the zone. This will likely limit the wet loose avalanche problem on Monday. However, with some sun in the forecast, southern slopes could experience a round of warming that induces loose avalanches or creates a more cohesive slab over our various crusts and weak layers. If you feel the snow warm up, get sticky, or begin to rollerball, consider moving to shady or lower-angle terrain. 

On Sunday, an NWAC forecaster in the Salmon La Sac area reported widespread natural avalanche activity throughout the terrain. Lower elevations saw many wet loose and wet slab avalanches, and ridgelines were peppered with an abundance of small crowns. These avalanches were primarily small, likely involving just the recent snow. But it's a testament to the weak surface hoar layer recently buried. We expect most of this activity to have run it's course during the warm temperatures and peak precipitation, especially after a cool night forms surface crusts. However, these persistent and tricky layers could still be reactive if you find cold, dry snow. The further north and east you are in the zone, the more likely you are to find dry snow at mid and upper elevations. 

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