Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Another storm favoring the southern Cascades will bring moderate winds, snow, and lowering freezing levels. You can trigger avalanches in wind drifted snow at upper elevations. Steep ridgelines are the most likely places to find these slabs, but best to avoid any steep slopes where you find these stiff, pillow-like drifts. 

Avalanche problems

  • Wind Slabs

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

    We have significant uncertainty and limited information on snowpack conditions from the terrain at these elevations. However, continued light to moderate snow with 10-20mph winds is enough to build unstable wind slabs. These shallow fresh wind slabs may form over slick melt-freeze crusts, potentially making them sensitive to triggers. Probable locations to trigger these avalanches are near ridges, the base of cliffs/rocks, or convex rolls in terrain. You can recognize wind slabs by their pillow-like form and potentially hollow sound. Textured surfaces, cornice formations, and drifts behind trees and rocks can also point to likely wind slab locations. Watch for signs of instability, such as shooting cracks or collapsing. Avoid steep wind-loaded slopes by traveling on the scoured windward side of ridges or sticking to wind-sheltered terrain. 

    (1/4/2023)

    A very shallow wind pocket failed. Notice the textured surface and how it looks "fat" compared to the surrounding terrain.

    Photo: Dallas Glass

Avalanche Discussion

Low-elevation trailheads below 3500ft may continue to see precipitation in the liquid form, making wet loose avalanches possible. Where there are steep rocks and cliffs, these wet avalanches may break as wet slabs and be large enough to bury a person. Avoid steep terrain where you are sinking deeply into wet, heavy snow, and be cautious of traveling below steep rocks and cliffs. We are at the tail end of a widespread natural avalanche cycle. Many locations saw very large wet avalanches running long distances and impacting low elevation terrain. WSDOT NCR avalanche crew reported multiple D2 wet slab avalanches, with a couple up to size D3. The snowpack is draining water, temperatures are cooling, and the main event seems to be behind us. We are just beginning to get a handle on the extent of this avalanche cycle and the current state of the snowpack. Last week, I traveled into the Soup Creek area. Most notably, I found deep pockets of wind-drifted snow and observed active wind transport along ridgelines. In some places, up to 3 feet of snow rests over the Christmas Crust. I traveled on multiple aspects and elevations around this zone and was able to locate buried surface hoar in sheltered areas on northerly aspects in meadows and sparsely treed slopes. The snowpack likely looks significantly different after this warm storm, and an NWAC forecaster noted rocks emerging on steep south-facing slopes on Saturday. Rain probably destroyed this weak layer at low and mid elevations. But these persistent weak layers could be preserved above 6000ft, where precipitation remained as snow. So as you get out to enjoy the new snow, assess snowpack conditions as you travel. Use test slopes to monitor how the new snow bonds with underlying surfaces and heed warning signs such as shooting cracks, recent avalanches, and collapsing.

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