Bulletin d’avalanche

Summit Lake

Chugach National Forest Avalanche Center
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Danger d’avalanche

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

Points saillants

Wind slabs around a foot deep may be easier to trigger where they have formed on top of a layer of buried surface hoar. This problem will most likely be found above 2,500’. There is also a small chance of triggering a large avalanche on weak snow buried near the bottom of the snowpack. 

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SPECIAL ANNOUNCEMENTS:

We are sorry to report a fatal avalanche accident that occurred outside of Girdwood on the afternoon of March 4, 2025. Three people were caught and killed in an avalanche in the west fork of the Twentymile River. Ongoing recovery efforts are being coordinated by the Alaska State Troopers. We extend our deepest condolences to the friends and families of all parties involved. We have posted a preliminary accident report on our website. 

Problèmes avalancheux

  • Wind Slabs

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

    It could be easy to trigger a wind slab avalanche up to a foot deep above the treeline. There are a variety of layers these wind slabs formed on top of which may make them more reactive. The most concerning setup is a wind slab on top layer of buried surface hoar. This is the same problem we have in Turnagain Pass. For now there is much less snow over this weak layer and the avalanches are smaller. This was the case for a human triggered avalanche on Tenderfoot earlier this week that failed on buried surface hoar. Wind slabs have also formed over a slick crust that may take longer to bond together. A sun crust was observed at from 2,200' to 2,600’ on solar slopes and is likely higher. 

    Wind slabs are more common in steep terrain below ridgelines, rollovers (convexities), and in loaded gullies. Look for shooting cracks and test small wind loaded slopes. Look out for shooting cracks and snow that becomes stiff. These are clues you are traveling on a wind slab.

    (3/3/2025)

    Looking down towards the path. The avalanche ran about 1,000' and the powder cloud went to the valley bottom.

    Photo: Mik Dalpes

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    2–3

    There are still weak layers close to the ground that could trigger a large avalanche. This problem is most concerning in upper elevation bowls where deep snow becomes thin. Areas where the snowpack is thin (near exposed rocks and on ridgelines) are the most likely places to collapse and trigger these weak layers.  

Régions couvertes