Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Look for freshly forming wind slabs as you gain elevation on Monday.  Continue to travel vigilantly on upper elevation, shaded slopes where weak, faceted snow lingers deeper in the snowpack.  Shallow snow conditions persist below treeline, so tread lightly with your sled or skis. 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Light snowfall on moderate to strong west winds will create shallow wind slabs on lee terrain features.  You will specifically find these areas of wind drifted snow on slopes that face east, under cornices, and scattered through the alpine.  Due to the high winds, you may find these slabs forming further down on slopes than usual.  These newly forming areas of wind drifted snow should be easy to spot and avoid.  Look for wind textured snow surfaces, slopes getting actively wind loaded, and areas that look rounded or pillow-like.  

    (12/14/2022)

    Blowing snow is a great way to anticipate where potential wind slabs are living. 

    Photo: Willie Webster

  • Persistent Slabs

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

    Persistent slab avalanche problems take time to heal. Current observations have been limited across the east-south, however adjacent zones are dealing with a similar snowpack structure.

    Dig down into the snow and look for sugary, weak grains near the bottom of the snowpack from late November.  You can use snowpack tests such as compression tests or extended column tests to locate these possible weak layers.  

    There is some uncertainty with the distribution of these weak layers across the east-south. That being said, the most likely spot you can trigger a large persistent slab avalanche is on higher elevation slopes that face north and east and have been recently wind-loaded. 

    Stick to lower angle terrain if you observe recent avalanche activity, see shooting cracks under your skis/sled, or hear whumphs. 

Avalanche Discussion

Observations have been quite limited across the east-south zone, so if you get out, please-please submit an observation!  Even just a picture can go a long way. 

These light trickles of snowfall will be falling on a patchwork of snow surfaces such as preserved cold snow in sheltered areas (including surface hoar and near-surface facets),  wind affected snow in the alpine, and a sun crust on steep solar aspects.  As new snow piles up, keep an eye on if surface hoar and near-surface facets are getting buried. This weak surface snow could be tomorrow's weak layer.  

Regions covered