Bulletin d’avalanche

West Slopes North

Northwest Avalanche Center
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Danger d’avalanche

Tue
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré 6 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Fresh snow and strong wind winds will create dangerous avalanche conditions Monday.  You'll likely be able to trigger a wind slab avalanche on a variety of aspects and elevations, and potentially further downslope than usual. 

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2

    Strong winds will redistribute the new snow onto a variety of aspects Monday.  While snowfall totals should end up in a modest 8-12" range, the wind is expected pack a punch.  Particular to this storm, think about wind slabs forming further downslope and below ridgelines than your usual garden variety PNW storm. 

    Avoid all open lee slopes steeper than 35 degrees where you suspect winds slabs may have formed. Watch for cracking in the new snow as a sign of instability and feel for areas of stiffer wind-pressed snow as you change aspects and elevations. To avoid the problem you can always choose wind sheltered and lower-angle terrain not connected to steep open slopes above. 

    (11/28/2020) Skier triggered slab avalanche in the Mt Baker backcountry on a wind loaded slope.

Avalanche Discussion

Several human triggered soft slab avalanches, generally small, were observed in backcountry terrain near the ski area over the holiday weekend. With the incoming storm on Sunday night and Monday our attention is turning to avalanches that fail within new storm layers or at the new snow/old snow interface. 

Snow depths range from 40-65 inches throughout the North Cascades, and continuous snow begins near 2500-3000ft. Snow coverage is well above average for this time of year, but early season conditions still exist. Stay alert for open creeks, tree wells, crevasses, or other exposed hazards. Consider the consequences when choosing terrain. Falling or getting caught in even a small avalanche could result in a rough ride.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

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