Bollettino valanghe

East Slopes North

Northwest Avalanche Center
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Pericolo valanghe

Mon
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 6 months ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Conditions are changing, and slab avalanches will be easier to trigger on steep, wind-exposed slopes. Easterly winds will drift snow in unique areas. If you see blowing snow, long cracks on the surface, and stiff-feeling snow, stick to slopes under 35 degrees.

Problemi valanghivi

  • Wind Slabs

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

    Wind slab avalanches will be shallow but could be easy to trigger on favored peaks and ridges. Stay alert and observant to clear signs of the danger: recent slab avalanches, blowing snow, long, shooting cracks in the snow, fresh cornices, and wind-stiffened surfaces. You should be able to keep from triggering slides by steering around steep roll-overs or staying off of aprons under cliffs. 

    The east wind can be more driven by terrain, so you'll find the most slab development on slopes that are near passes, gaps, and long east-west running valley corridors. You can test small, inconsequential slopes to see if they slide. If you see signs of wind slab conditions, stick to slopes under 35 degrees or wind-sheltered terrain. If you see widely propagating avalanches, put lots of space between your group and any avalanche terrain.

    (2/18/2026)

    Skiers triggered very shallow wind slab avalanches on the 18th.  Silver Star Mtn, middle elevations, N-NE

    Photo: NCH

  • Loose Dry

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    Natural and human-triggered loose avalanches could be fast-running on an older melt-freeze crust on slopes near 40 degrees. While they may be small and predictable, they could push them into gullies, trees, or cliffs. If you observe long-running sluffs, practice good terrain management, stop out of the runouts in steep terrain, and use extra caution around consequential terrain. 

    (2/7/2025)

    An example of natural loose dry avalanches from last season near Washington Pass.

    Photo: NCH

Avalanche Discussion

There's a decent amount of snow available to be blown by wind, and there's widespread weak snow over crusts on most slopes. On the 21st, observers reported very shallow cracking (1-2") limited to the immediate leeward sides of ridges, as well as triggered loose dry avalanches at upper elevations. Light snowfall and cold temperatures over the past 2 weeks have built a very weak upper snowpack. The wind and soon snowfall are adding the final element for very dangerous conditions. With more wind, snow, and warming temperatures forecast through next week, the region is primed to develop a dangerous, long-lasting, persistent slab hazard. 

While we're not there yet, it's possible that we'll see very reactive avalanches and dangerous conditions in the coming week. The main concern is new and drifted snow forming slabs on a widespread weak layer over a crust. On all but southerly aspects, there's 8-12" of dry, weak snow over the upper crust (February 7th). The layer immediately above the crust is extra weak with larger faceted grains and surface hoar. The January 28th crust is thicker and now 12-16" below the surface.  On southerly aspects, there are more crusts and less dry, weak snow on the surface. Further west of Washington Pass, the crust may be thicker and deeper with more dry snow between them. Farther east, in places like the Chewuch and Twisp River drainages, the snowpack is shallower and weaker. Here, the crusts have become faceted on shady aspects, with the upper 2/7 crust barely discernible in some northerly terrain.

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