Lawinenlagebericht

Seward and Lost Lake

Chugach National Forest Avalanche Center
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Lawinengefahr

Mon
Hochgebirge
3 · Erheblich
Waldgrenze
3 · Erheblich
Unterhalb
2 · Mässig
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Veraltet — dieser Lagebericht ist last year abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

There is still a good chance a person could trigger a very large avalanche failing 1 to 3' deep on a weak layer of buried surface hoar. This has been making avalanches for nearly three weeks now, and remains reactive today. The layer can be very hard to assess for a specific slope, the best way to manage this problem is to avoid steep terrain for now. Keep in mind, these avalanches are often triggered after there are already multiple tracks on a slope, and they may be triggered from low-angle terrain connected to steeper slopes. It may also be possible to trigger a smaller avalanche up to a foot deep where recent winds have drifted snow into reactive slabs above treeline.

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SPECIAL ANNOUNCEMENTS:

Come find us at the Seattle Ridge motorized parking lot on Saturday, March 22 for our annual Turnagain Pass Avalanche Awareness Day! We will be there with Alaska Mining and Diving Supply and the Alaska Avalanche School to chat about avalanches and current conditions and to hang out with the good people of the southcentral Alaska winter community. AMDS will have demo snowmachines, and we’ll be holding down the grill and the fire pit. Stop by anytime from noon until 4:00 p.m. Details Here.

Lawinenprobleme

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    2–3

    Recent Avalanches: There have been several avalanches in the Turnagain Pass area, which has a similar snowpack to the Seward/Lost Lake zone. This includes one very large avalanche triggered remotely near the Seattle Creek Headwall sometime since Thursday, which was around 1,000 wide and 1-2' deep. See Wendy's observation from yesterday for photos and some more info. The last human-triggered avalanche activity that we are aware of in the Seward zone was several smaller avalanches triggered near Lost Lake last weekend.

    We are still seeing clear signs of concern from the weak layer of buried surface hoar that is anywhere from 1 to 3 feet deep and has been causing avalanches for almost three weeks now. Although it is slowly becoming more stubborn, people are still triggering big avalanches. This problem has been very hard to assess for a specific slope because it does not show up in every snowpit, and has been giving mixed results in stability tests. However, the fact that we continue to see people triggering large avalanches is all the information we need to know that it is still a major problem. We've also seen several avalanches failing on a more recent layer of surface hoar that was buried a week ago and is now around a foot deep.

    Because of the unreliable feedback we're getting from snowpits, the only way we can really manage this problem is by avoiding steep terrain. If you are considering getting on steeper slopes it will be wise to choose low-consequence terrain, avoiding large slopes or anything above terrain traps like gullies, cliffs, or trees. This type of problem will often produce avalanches even after there are multiple tracks on a slope. We have also seen many avalanches triggered remotely, from low angle terrain adjacent to steeper slopes. This means you may be able to trigger an avalanche from the bottom of a slope, even when you are on flat terrain. 

    Glide avalanches are also still an issue and we have seen several recent glide avalanches release near Girdwood this week. Try to avoid traveling underneath glide cracks or expose one person at a time to minimize time underneath these unpredictable hazards. 

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    The mountains near Seward have seen slightly stronger winds than the other forecast zones. These have been blowing out of the northwest for the past 24 hours, and have likely built sensitive wind slabs above treeline. These avalanches would likely be on the smaller side, but they have the potential to step down to the bigger avalanches described in Problem 1 above. Look out for unstable conditions in steep terrain below ridgelines, convex rollovers, and loaded gullies. These will feel like stiffer snow sitting on top of softer snow, and they may give you warning signs like shooting cracks or collapsing when conditions are unstable.

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