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
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

Temperatures have cooled off in the last few days, so the biggest concern in Summit Lake is the potential for a person to trigger a large avalanche on the buried surface hoar that is now up to 2' deep. Ridgetop winds picked up last night blowing new snow into fresh wind slabs up to 1' deep in the upper elevations. Wet snow problems are less likely today, but if the sun comes out, the snow could heat up quickly making wet loose avalanches a concern. New glide avalanches were observed yesterday in Turnagain Pass so watch for glide cracks and avoid spending time underneath. 

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SPECIAL ANNOUNCEMENTS:

Avalanche Closure Notification for Wednesday April 9th, 2025, Seward Hwy AND Portage Glacier Hwy

There will be intermittent traffic delays Wednesday April 26th, 2025, on the Seward Highway and Portage Glacier Highway for Avalanche Hazard Reduction work. From mileposts 83 to 88 on the Seward Highway, South of Girdwood and North of Portage, motorists should expect delays of up to 45-60 minutes between 09:00 AM and 12:00 PM. AND From milepost 3 to 5 on the Portage Glacier Highway, motorists should expect delays of 45-60 minutes between 11:00 AM and 2:00 PM. Updates will be posted on the 511 system. http://511.alaska.gov

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

  • Persistent Slabs

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

    New snow over the last 5 days or so has added some stress to the surface hoar that got buried on Valentine's Day. This weak layer is now between 1 to 2' deep in Summit Lake.  This layer has proven to be difficult to assess and produced unreliable test results making it difficult to trust in Turnagain Pass. If you are getting out on steeper terrain choose smaller slopes without terrain traps below like gullies and creeks. Or we can avoid this entirely by sticking to low angle slopes.

    Storm totals below are from 12 AM Friday morning through 6 am this morning:

    • Portage: 11.4" Snow Water Equivalent (SWE), equaling 6 to 9' snow above treeline. 
    • Girdwood: 5.2" SWE equaling 3' snow. 
    • Turnagain Pass: 3.2" SWE equaling 12-30" snow.
    • Summit Lake: 0.9" SWE equaling 6-8" snow.
    • Seward/Lost Lake: 2.9" SWE equaling 16-24" snow.

  • Wind Slabs

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

    Winds increased last night forming some small fresh wind slabs in the upper elevations. Unlike the difficult persistent slab, wind slabs are easier to assess. Watch for blowing snow and avoid places where it is accumulating. Feel for firm snow over softer snow and watch for shooting cracks that indicate the snowpack needs time to adjust. Jumping on small test slopes can also give us information about new wind deposited snow. 

    (3/20/2025)

    This photo is from a few weeks ago, but it shows wind blowing snow off Butch Mountain. Look for this today and avoid places where the snow is landing and building slabs.

    Photo: Mik Dalpes

  • Wet Slabs

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

    Things have cooled off a bit since last weeks meltdown, but the sun could come out today, which could heat things up really fast. Rollerballs are the first indicator of wet avalanche problems on the horizon. Wet loose avalanches could be next and wet slabs could still occur although those are less likely with the cooler temperatures. Glide avalanches continue to release in Turnagain Pass as of yesterday and the same could happen at Summit Lake. 

     

     

     

    (4/8/2025)

    Very large glide noticed the morning of April 8 on Seattle Ridge in Turnagain Pass. 

    Photo: Carolyn Spencer

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