Bulletin d’avalanche

Summit Lake

Chugach National Forest Avalanche Center
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Danger d’avalanche

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

Points saillants

Triggering a slab avalanche 1-2' deep on top of weak, faceted snow is the main concern in the Summit Lake area. The safest option would be to avoid stiff snow in steep, wind loaded slopes and look for soft snow that has been sheltered from the wind. 

Large glide cracks are opening and glide avalanches are releasing on all aspects in mid to upper elevations. They are unpredictable and traveling underneath them should be avoided whenever possible. 

Problèmes avalancheux

  • Persistent Slabs

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

    There is still a small chance of triggering an avalanche where stiff, wind loaded snow is sitting on top of a buried layer of weak snow. The most conservative option would be to avoid traveling on steep, wind loaded slopes. 

    At the moment it is hard to be sure how likely it is to trigger a persistent slab avalanche. We have not seen or heard of an avalanche in the past 10 days. Summit Lake has not received snow in more than 10 days and there may not be enough snow available to be blown into a slab and cause a natural avalanche. We also do not have enough information from field days or observations to know how likely it is for a human to trigger an avalanche on this weak layer.

    Weak layers like this can be stubborn until you have made several turns on a slope triggering a larger avalanche than expected. Watch out for stiff snow and shooting cracks or whumpfing underneath you. Consider that there may be no red flags indicating how dangerous the slope is. On the flip side, snow sheltered from the wind, will be soft and safer than firm wind slab snow.

  • Glide Cracks

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

    Although there is more glide avalanche activity in Turnagain, new cracks are still forming and releasing into glide avalanches in Summit Lake. Try to avoid traveling directly under these brown cracks and only expose one person at a time if you must move past them on your trip.

    This avalanche problem is impossible to predict because these cracks release spontaneously and are usually large enough to travel to the bottom of valleys and cover up skin tracks. They have been observed in and above treeline on all slopes as well as on north aspects where glide cracks/avalanches seem less frequent.  

    (11/25/2024)

    Large glide avalanche on the north face of South Wilson Peak. 

    Photo: Mik Dalpes

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