Bulletin d’avalanche

West Slopes North

Northwest Avalanche Center
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Danger d’avalanche

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

Points saillants

Expect new snow and southwesterly winds to form fresh drifts in leeward terrain on Friday. Use visual clues to help identify and avoid areas of wind loaded snow on upper elevation slopes greater than 35 degrees. 

Problèmes avalancheux

  • Wind Slabs

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

    Triggering an avalanche will be most likely on north through east aspects above 4500ft near ridge crests, in gullies, and in unsupported terrain. Up to 4-6in of new snow may fall over the next 24hrs and may not bond well initially to the old snow surface.  Avalanches could fail within new snow or on a firm crust formed Wednesday. Pay attention to changing conditions with aspect and elevation. Watch for cracking in the new snow as a sign of instability, and look for sudden changes in snow surface texture and hardness. To avoid the problem you can always choose wind-sheltered and lower-angle terrain not connected to steep open slopes above.

    (12/10/20) A skin track filled in by windblown snow. Watch for evidence like this to signal wind slabs may exist nearby as you gain elevation and transition into wind affected terrain

Avalanche Discussion

The Heather Meadows weather station (4200ft) at Mt. Baker Ski Area recorded over 3in rain between December 7-9 before precipitation transitioned to snow. On Thursday, observers in the Bagley Lakes/Artist Point area found  4in of new snow atop a firm and frozen rain crust. A wet avalanche cycle occurred during the rain event but appears to have run its course. Frozen debris piles were visible on many slopes under the few inches of new snow.  Some wet loose avalanches entrained significant snow as they ran downslope and grew large. A handful of glide avalanches occurred as well, and several glide cracks are still visible. Even though cool temperatures have allowed the snowpack to freeze and gain strength, build in a wide margin of error and continue to avoid slopes with open glide cracks.

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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