Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

Fri
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

A fast-moving storm will bring new snow, strong winds, and rising avalanche danger Thursday. Large avalanches in wind-drifted snow will be easy to trigger by the afternoon at upper elevations. Avoid wind-loaded features 35 degrees and steeper and seek out wind-sheltered or lower-angle terrain to reduce your risk.

Avalanche problems

  • Wind Slabs

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

    New snow and wind will form fresh and reactive drifts in all elevations bands with the most dangerous avalanche conditions developing Thursday afternoon. Existing slabs formed over the past week of steady snowfall are still healing, and additional loading will not help the situation. Incoming snow will fall on cold, weak old snow surfaces and may not bond well. Cornices are also a concern and are overbuilt along some ridgelines. If they fall, they could act as large triggers on slopes below.

    Pay attention to changing conditions throughout the day. Westerly winds up to 50mph will easily transport new and existing low-density snow into thick drifts. Travel cautiously if you transition into wind-affected terrain. With snow depths tapering from west to east, expect larger and more sensitive wind slabs in areas closer to the Cascade Crest. 

    (12/28/2021)

    Look for fresh cornices along ridgelines as an obvious sign of wind loading.

    Photo: Andy Harrington

Avalanche Discussion

Blowing snow and wind loading should be widespread Thursday. Visibility will be poor and avalanche conditions will worsen throughout the day. By afternoon, choose simple, supported terrain and avoid travel in the runout of large avalanche paths.

There are still exposed rocks and trees in areas further east in the zone and at lower elevations. The deepest snowpacks are around Mt Aix and Bumping Ridge. The solstice crust is buried approximately 2-3 feet deep near the Cascade Crest and 5-6 inches deep in the eastern parts of the zone. Current reports indicate that the storm snow is bonded well to the solstice crust. However, we have limited observations from the upper elevations, resulting in significant uncertainty about snowpack conditions in alpine areas. There have been reports of weak snow surrounding the December 8th melt-freeze crust in neighboring zones. It is worth approaching new terrain slowly and evaluating the snowpack as you venture into higher elevations.

If you are out riding in the East South Zone, please let us know what you see by submitting an observation. 

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