Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

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

After a cold clear night, another storm will move into the southern Cascades late Wednesday morning. You can still trigger avalanches in wind drifted slabs of snow formed over the last few days. Winds have repeatedly shifted directions, and you may find unstable snowdrifts on all aspects near ridgelines. Steer around steep terrain with pillow-like drifts of snow.

Avalanche problems

  • Wind Slabs

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

    The wintery, unsettled weather pattern continues. After a brief break overnight, strong gusty winds will pick up. Light snow is also expected, with the highest accumulations near the crest. Although Tuesday was warmer and sunnier than expected, plenty of snow is still available for transport, building new shallow wind slabs near ridgelines. Both fresh and older wind slabs can be found on most aspects and potentially in unusual locations. Use visual clues like blowing snow, textured surfaces, or cornices to help you identify and avoid freshly wind-loaded slopes. Since recent snow may cover older wind slabs, they may be more difficult to identify visually, but you can use your pole or probe to feel for stiffer layers in the upper snowpack. With minimal direct observations and uncertainty about the distribution and sensitivity of these overlapping wind slabs, entering new terrain slowly and making observations before committing to steep terrain in wind-affected areas is important. If you see signs of instability such as shooting cracks or feel the snowpack collapse beneath you, move to lower angle or wind-sheltered terrain.

    (4/11/2022) Wind slabs were found in some unusual spots. Fresh slabs were observed on slopes often stripped by the wind. Photo: Dallas Glass

Avalanche Discussion

On Tuesday, areas near the Cascade crest picked up around 10 inches of fresh snow, with accumulations tapering further east in the zone. Wednesday will likely start with clear skies in the morning, but clouds will quickly build into the region, followed by strong, gusty winds and light precipitation. The Cascades have been in a tricky weather regime for over a week, with shifting winds, atypical storm patterns, and sun breaks when we expected clouds. This weather has increased uncertainty in both the weather forecasts and the avalanche forecasts. It is not unusual for spring weather to be challenging to forecast, and you should plan for some of this uncertainty when you head out into the mountains. Keep your senses tuned into the snow and look for signs of deteriorating snow stability such as recent avalanches, wet snow surfaces, actively blowing snow, and heavy snowfall.With the strength of the spring sun, even short sun breaks can make the recent snow wet and heavy quickly, making wet loose avalanches possible. So if you find yourself on slopes in direct sun with snow surfaces becoming moist or rollerballs forming, it will be best to move to lower angle or shady terrain. Even a small wet loose avalanche could be consequential if it knocks you off your feet and carries you into trees, rocks, over cliffs, or buries you in confined terrain.

Snow surfaces melted from recent rain, warm temperatures, and sun on Monday and Tuesday. Cold temperatures overnight on Tuesday will refreeze these surfaces, creating challenging travel conditions on thick, icy, and breakable crusts. Access into areas of the East South with a consistent snowpack has become challenging, and therefore direct observations from the zone are limited. However, snow is piling up on more recent melt-freeze crusts from 4/18, and the 4/8 Crust is now 2-4 feet deep. It is worth digging down to investigate these interfaces before committing to any steep terrain. Some southern slopes that were recently snow-free up to 5700ft may now have over a foot of snow. Use extra caution in these lower elevations where obstacles may be lurking just under the new snow, and creek holes may be drifted over or hidden.

Regions covered