Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

You can trigger slab avalanches in fresh pockets of drifted snow at middle and upper elevations. Any triggered avalanche has the potential to grow much larger and really pack a punch if they fail on a weak layer 2-4 ft below the snow surface. Shape your travel plans so you avoid open slopes greater than 30 degrees - especially if they appear wind drifted. 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Low density new snow will easily drift into reactive slabs in more exposed areas. Recent east winds may have drifted snow onto unusual aspects like west aspects or across terrain features, so keep an eye out for these as you change aspects. 

    Blowing snow and drifting should show exactly what aspects are loading up. As you move through the terrain, pay attention to changes like snow stiffness and texture. You can look for surface clues like sharp cornices, rippled snow, and pillow-like slabs to help you identify problematic slopes. Pull back and default to less steep slopes if you notice obvious signs of instability like shooting cracks or audible whumping. 

    Any triggered wind slab has the potential to step down to old snow and break wider and deeper than expected. Your best bet will be to carefully evaluate and avoid steeper terrain that appears to be wind-affected. See more below.

    (3/4/2023)

    Cornices often point in the direction of wind loaded aspects.  

    Photo: Joe Dellaporta

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    You can trigger large avalanches on various weak layers that now sit 2-4 ft below the snow surface. These avalanches can act in surprising ways, and be triggered from adjacent slopes.As this active period tapers, you may become less likely to trigger these avalanches - but unfortunately, the consequence stays the same. Since these avalanches can really pack a punch, you’ll want to increase your margins by seeking out more sheltered slopes less than 30 degrees at middle and upper elevations. 

    (1/10/2024)

    Backcountry travelers near Lake Wenatchee remotely triggered this avalanche from a low angle adjacent slope. This avalanche ran on weak, facted snow over the Solstice Crust.

    Photo: Pat Riffie

Avalanche Discussion

The recent storm layed down 8-10 inches of low density new snow in favored locations across the East South. The riding conditions are becoming all time, but be aware of monsters lurking in the basement.

Observations from both the West South and East Central have illustrated avalanches breaking in surprising ways and failing on old snow above the solstice crust. For example, Mission Ridge Pro Patrol triggered multiple avalanches that failed on weak, faceted snow over the Solstice Crust, and a backcountry traveler near Lake Wenatchee remotely triggered a small avalanche on a steep convexity on this same layer. Buried surface hoar (1/2) was responsible for two other human-triggered avalanches before this storm. We have yet to hear about more recent avalanches on this surface hoar layer, but it could still be an issue. With both layers potentially lurking below the surface, extra caution and wide safety margins in your travel plans are warranted. 

If you get out, let us know what you see by submitting a public observation. 

 

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