Bulletin d’avalanche

Summit Lake

Chugach National Forest Avalanche Center
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Danger d’avalanche

Tue
Alpin
3 · Marqué
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

It will be easy to trigger an avalanche where winds have blown snow into reactive slabs up to a foot deep. This will be most concerning above treeline in terrain just below ridges, convex rollovers, and in loaded gullies. You can manage this problem by avoiding these terrain features, and for looking out for slopes with stiff snow on the surface. There is also a much smaller chance of triggering a much larger avalanche on weak snow buried 3 to 5' deep.

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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.  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

  • Deep Persistent Slabs

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

    The weak snow buried deeper in the snowpack is still in the back of our minds. This hasn't produced any avalanches recently, and it is unlikely a person will be able to trigger an avalanche on it today. However, we are still seeing it in our snowpits, and it is enough cause for concern that it is keeping us out of big consequential terrain. The odds are small, but the consequences are large. Keep this layer in mind as you are assessing terrain today, and consider avoiding slopes with large start zones or consequential runout zones for now.

  • Wind Slabs

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

    Unfortunately, the storm that impacted the area yesterday only brought wind to the Summit Lake zone. This has made a fresh layer of wind slabs that may be sitting on top of the same layer of buried surface hoar that has been making avalanches throughout the region from Girdwood to Seward. Winds are expected to slowly ease through the day, but will continue moving snow into the evening. These will be bigger and more reactive above treeline, and are most likely to be found in steep terrain below ridgelines, convex rolls, and steep gullies.

    There are a few ways to manage this problem. The easiest way is to avoid all steep terrain. But you can also evaluate the snowpack as you travel, avoiding slopes with stiff snow sitting on top of softer snow. Any signs like shooting cracks or collapsing are clear indicators of unstable snow. Small test slopes may provide some information on how this latest round of wind slabs is behaving. The best surface conditions and most stable snow will be found in terrain that has remained protected from the winds.

    (3/6/2025)

    The wind slabs that formed yesterday and continue to build this morning are sitting on top of this layer of surface hoar. This will make them more reactive for a longer time.

    Photo: Daniel Krueger

Régions couvertes