Lawinenlagebericht

Galena Summit & Eastern Mtns

Sawtooth Avalanche Center
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Lawinengefahr

Sun
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
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Veraltet — dieser Lagebericht ist 4 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

Triggering a 1-2 foot thick avalanche in wind-loaded terrain remains possible. Avalanches failing on deeper weak layers are less likely but can't be ruled out in rocky, wind-affected terrain. You can significantly reduce your risk by steering clear of slopes steeper than about 35 degrees.

Lawinenprobleme

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1.5–2.5

    Several weak layers are buried in the upper 1-2 feet of the snowpack. On slopes that face away from the sun, you'll find some surface hoar and facets at these interfaces. On slopes that face the sun, you'll find crusts with some small facets here. Moderate to strong winds this week created a batch of stiff wind drifts in terrain exposed to the wind, building slabs on top of these buried weak layers. Thursday, skiers on Titus Ridge found this combination of unstable slab+weak layer when they remotely triggered a small wind slab from 50 feet away (photo here).  Cracks shooting out from your machine or skis are clear indicators of an unstable slab. Small slabs that knock you off your feet and send you downslope can have high consequences in the wrong terrain.

    Further down in the snowpack, you'll find layers of weak snow near the ground. Triggering an avalanche on these layers is most likely in wind-affected alpine terrain where scouring has produced thinner areas of the snowpack. Here, you'll have better access to this weak snow and triggering a slide involving it remains possible. I skied in this zone both of the last two days and the presence of this weak snow dictated the terrain that I was comfortable entering. 

    Avalanches failing on persistent weak layers can break well above you on the slope and may break wider than you expect. You can significantly reduce your risk by steering clear of wind-affected, rocky, alpine terrain steeper than about 35 degrees.

Avalanche Discussion

After a strong start to the season, snowfall in January largely missed this zone. Because of that, the snowpack has remained thinner here and the weak layers we buried in November, December, and January are all still "in play" in this zone. Several weak layers can be found in the upper few feet of the snowpack here. Layers of surface hoar exist on sheltered, shady slopes, while crusts with and without facets on top can be found on slopes that face the sun. In most places, the slab overlying these weak layers isn't thick enough to produce avalanches in sheltered terrain. You're most likely to get into trouble with these upper weak layers in places where the wind has been at work building slabs and stiffening the snow surface.

Weak snow deeper in the snowpack continues to be worrisome in this zone. I spent the past two days skiing in this zone and the presence of this weak snow dictated the terrain that I was comfortable traveling in. You're most likely to trigger a slide involving these older weak layers in rocky, wind-affected, alpine terrain. Slopes like these have variable snow depths, with thinner areas of the snowpack that make it easier to impact these weak layers. There is a lot of terrain that looks like this in the Pioneer, Boulder, and White Cloud Mountains, which make up the majority of this zone.

For more info on what happened last week check out Scott's latest Weekend Update.

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