Bulletin d’avalanche

Turnagain Pass and Girdwood

Chugach National Forest Avalanche Center
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Danger d’avalanche

Sun
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 9 months ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

We're still concerned that somebody will find a slope in the alpine where they can trigger a large avalanche on a weak layer of surface hoar buried 2-3' deep or deeper. It is very hard to identify where this layer is reactive where it is not, and it is unlikely to give any feedback before somebody triggers a big avalanche.  Because of this high uncertainty with assessing which individual slopes are dangerous and which ones are safe, it is still a good idea to avoid steep, complex terrain for now. We're also expecting the ongoing glide avalanche cycle to continue, so be sure to avoid lingering under any steep terrain, especially if there is an open crack on the slope.

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Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–2.5

    Recent Avalanches: It's been just over a week since the last significant natural avalanche cycle in the Turnagain Pass, which was concetrated on the back side of Seattle Ridge.  During that same time frame, we saw multiple human-triggered avalanches on Sunburst and the Tincan trees.  New glide avalanches continue to be observed daily in Girdwood, Turnagain Pass, Summit Lake, and Seward.

    We're in a bit of a holding pattern with these persistent weak layers of buried surface hoar. There are actually three layers of buried surface hoar in the upper 3' of the snowpack, and any of those may still produce large avalanches. It has been over a week since the last known avalanche failed any of these weak layers, but with so little traffic in the backcountry since last weekend it is really hard to say if that's because they're gaining strength, or if it's just because people haven't been getting into the terrain where the layer is problematic. Most likely it is some kind of combination of both.

     Based on what we've been seeing in the snowpit, we know these layers are still present, and it is likely there are still plenty of steep, upper elevation slopes where a person can trigger a large avalanche. These layers are notorious for giving misleading results in a snowpit even when conditions are dangerous, and they may not give any warning signs before someone triggers a big avalanche. The most suspect habitat for this weak layer lies in steep terrain above around 2500'. Keep this dangerous setup on your mind if you are headed into the alpine to get to the good surface conditions. For now, we're still avoiding traveling in steep, complex terrain while we suss out just how reactive the snowpack still is.

    Wind Slabs: We are expecting to see northeasterly winds pick up this afternoon into tonight. These will start to blow snow into reactive slabs up to a foot deep in upper-elevation start zones, especially just below ridgelines, in steep gullies, and below convex rollovers. While not nearly as big as the other avalanches we are concerned with, this is another thing that will be important to pay attention to as the winds pick up.

    (12/4/2025)

    Buried surface hoar about a foot deep on the front side of Seattle Ridge at about 2800' elevation.

    Photo: Graham Predeger

  • Glide Cracks

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

    The glide avalanche cycle continues, and even though temperatures started dropping yesterday, we're not expecting it to slow down. In fact, we often see a flurry of glide avalanche activity right after a cold snap. Ultimately, nobody has been able to predict exactly when a glide avalanche will release, so we're treating steep terrain with caution. One thing that is important to key into with this particular cycle is that we have seen several glide avalanches release without a previous glide crack on the slope. If you haven't seen the video from this glide avalanche in motion on Tri tip from Thursday, it's worth a look. These avalanches are big, and they are impossible to predict. The best way to manage this problem is to avoid lingering under steep terrain. Pay close attention to any steep slopes you are navigating, and be aware that even though you didn't see a crack in the morning, any steep slope is suspect now and worth paying very close attention to.

    (12/3/2025) Glide avalanche on the west face of Magnum.

Régions couvertes