Bulletin d’avalanche

Flathead Range & Glacier NP

Flathead Avalanche Center
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Danger d’avalanche

Sat
Alpin
2 · Modéré
Limite forestière
1 · Faible
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 4 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Watch for freshly formed drifts of snow below corniced ridgelines and in gullies. Move to wind-sheltered terrain if the snow cracks beneath your feet or machine. 

Problèmes avalancheux

  • Wind Slabs

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

    Yesterday (Thursday), observers noted southwest winds drifting recent snow into soft, stubborn slabs. Today, new snowfall and moderate gusts will increase the distribution and sensitivity of fresh drifts. Pay attention to changes in snow texture to identify where wind slabs exist.

    The older generation of wind slabs appears stubborn; however, don’t be lulled into trusting older slabs. In steep terrain, avoid riding on pillows of dense, thicker snow. You can avoid the problem by choosing terrain where the snow is sheltered or scoured by the wind.

    (2/16/2023)

    Moderate to Strong southwest winds transported snow on Nyack Mountain.

    Photo: MD

  • Persistent Slabs

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

    Weak layers of buried surface hoar and facets exist 1 to 2 feet below the surface in the Flathead Range and Southern Glacier Park. An observer yesterday (Thursday) experienced an audible collapse on a wind-scoured ridge above 5000 feet. You can manage this problem by sticking to terrain with lower slope angles and avoiding convex rollovers where you are more likely to trigger a slide. Even small avalanches have the potential to step down to buried weak layers. Choose slopes with runouts free from trees and cliffs to reduce your chances of trauma in the event of a slide. Conservative terrain choices increase your margin of error. 

     

    (2/15/2023) Northern Swan. NE aspect, 6300'. 24* slope.

Avalanche Discussion

Today we’ll be shifting back to active weather, but we’ll start in low gear. By most accounts, today’s snowfall should be light and accumulations modest. The Northern Whitefish Range and along the continental divide could see precipitation start earlier than the rest of the advisory area. If your travels take you to a favored location–where snow is stacking up earlier and faster than anticipated–consider ratcheting up your margins for safety. In wind-loaded terrain, greater snowfall rates can kick the wind slab machine into a higher gear. If you retreat to sheltered slopes, recognize that the new snow may sluff readily. These will travel faster and further on firm crusts.

Régions couvertes