Bulletin d’avalanche

Seward and Lost Lake

Chugach National Forest Avalanche Center
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Danger d’avalanche

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

Points saillants

Continued heavy snowfall across the forecast zone is creating dangerous avalanche conditions. Human-triggered avalanches 1 to 2' deep are likely and deeper avalanches up to 2 to 4' deep within the new snow are possible. If the sun comes out today the new snow could rapidly warm up and cause natural avalanches. In addition, the dangerous buried weak layer from mid-February is still very concerning after being stressed by all the new snow. We recommend sticking to low angle terrain and avoiding steep slopes overhead. 

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SPECIAL ANNOUNCEMENTS:

End of Season Operations: Starting next week we will transition to our late season schedule. We will issue avalanche forecasts on Tuesday, Thursday, Saturday and Sunday for the second half of April. We will issue our final forecast of the season on Sunday, April 27.

If you have been traveling in avalanche terrain for at least one season and want to help avalanche researchers develop new tools to assist individuals with managing risk in avalanche terrain, check out this 1-2 minute survey. Participants will be entered to win prizes from Jones Snowboards, BCA, and more!

Problèmes avalancheux

  • Glide Cracks

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

    During the brief breaks in cloud cover this week we have observed continued glide avalanches releasing across the region. This is part of the normal spring shed cycle, but these avalanches are unpredictable and very difficult to manage with limited visibility. The best way to avoid them is to steer clear of steep terrain overhead. If visibility allows, try to keep an eye out for glide cracks opening up that are often a precursor to avalanches releasing. 

  • Storm Slabs

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

    Due to weather station outages, we are unsure exactly how much new snow has fallen in the Seward and Lost Lake areas. Based on the weather forecast, the new snow amounts are probably similar to Girdwood and Turnagian Pass, which received another 12 to 15" of new snow in the past 24 hours.  

    Weekly snowfall totals from weather stations at 1400' to 1800' elevation:

    • Girdwood: 7" water, 40" snow
    • Turnagain Pass: 4.4" water, 28" snow
    • Summit Lake: 1.5" water, 10" snow
    • Seward/Lost Lake: Snowfall weather station not operational

    All the new snow this week means human-triggered avalanches 1 to 2' deep are likely within the new snow. Avalanches breaking deeper in the new snow, up to 2 to 4' deep, are also possible, especially in areas that received the heaviest snow totals this week. We recommend a very cautious decision-making approach today since the snowpack has not had a chance to adapt to the heavy snow load. Sticking to lower angle terrain and being mindful of any steep slopes overhead are good ways to enjoy the new snow while giving the snowpack time to adjust.

    The dry new snow from this week is sitting on top of a wet and weak snowpack that had already started transitioning to springtime conditions before the weather decided to switch back to winter. This is a fairly unusual snowpack setup and we are uncertain about how likely the new snow is to bond to the old wet snow surface. If the sun pokes through the clouds this afternoon it could cause rapid changes to the new snow, potentially inducing a cycle of natural avalanches as the new snow from this week heats up. 

    With the snowpack at its deepest point in the season and lots of soft snow on the surface, tree wells are a significant hazard right now. We received a report of someone caught in a tree well in the Tincan Trees yesterday but luckily they were able to climb out on their own. Additional hazards to look out for include cornice fall along ridgelines and loose snow avalanches on steep slopeswhich could grow quite large due to the amount of new snow. If winds pick up this afternoon wind slabs could form rapidly at upper elevations with lots of soft new snow available to be transported into fresh wind slabs. 

    (4/3/2025)

    Large natural cornice fall near Lost Lake. This was prior to the series of storms that has impacted the area since late last week, but we expect similar activity to remain likely.

    Photo: Daniel Krueger

  • Persistent Slabs

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

    The added weight from the 4 to 7" of water this week is a major stressor on the buried weak layer of surface hoar that we have been dealing with since mid-February. This layer is now buried 2 to 4'+ deep. As far as we know, no new avalanches have occurred on this layer this week but the visibility has been terrible and we have received very limited observations. We still don't trust this layer and recommend you avoid traveling on or below steep terrain. This type of weak layer can produce very large avalanches without any warning signs even on slopes with many tracks. 

Régions couvertes