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

The ongoing thaw will maintain tricky and dangerous avalanche conditions. Expect the likelihood and size of wet avalanches to increase throughout the day, while concerns for avalanches in wind-drifted snow still linger. It's uncertain how the snowpack will respond to this jarring transition from winter back to spring; build in a wide margin for error and consider avoiding avalanche terrain altogether.

Avalanche problems

  • Loose Wet

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

    Expect 8,000-11,000ft freezing levels for the next 24 hours. With such warm temperatures, snow surfaces won't have a chance to freeze and gain strength Wednesday night. Wet snow conditions will exist right out of the gate Thursday, and the strong April sun will beat down on the snowpack and accelerate the thaw. The most dangerous conditions will develop on E-S-W aspects in direct sun, but you could encounter wet snow on any aspect and elevation by afternoon. Avalanches will run naturally and will be easy to trigger on slopes 35 degrees and steeper. These avalanches may start small and shallow but could grow large and gouge deeper as it continues to heat up. Wet loose slides in motion could even trigger slabs resulting in surprising avalanches. Choose simple terrain away from large avalanche paths as the snowpack takes time to adjust to these dynamic conditions.

    Example photo of wet loose avalanches similar to what we expect on Wednesday.

  • Wind Slabs

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

    All the recent storm snow is still settling and stabilizing. Thickest and most reactive slabs linger near the Cascade Crest at upper elevations on easterly aspects. A large natural avalanche even occurred early Wednesday just outside of White Pass Ski Area in the adjacent West South zone. Avalanches could break on the new/old snow interface (Early April Crust) or within new and wind drifted snow. The warm-up adds uncertainty, and cornices could also fall acting as huge triggers on slopes below. Pay attention as you transition into wind-affected terrain, and continue to avoid steep, unsupported slopes with evidence of fresh wind loading. 

    (3/18/2022)

    Example of a wind slab near Darland Mountain. 

    Photo: Andrew Kiefer

Avalanche Discussion

It's rare to see such a cold winter storm immediately followed by such a dramatic warm-up. Wet loose activity was slow to develop Wednesday throughout the region, but the hazard should spike on Thursday. This may not be the average wet loose cycle you usually see on the first sunny days following a storm. These conditions are a very good recipe for avalanches due to:

  • The depth (1-3ft) and cold, low-density quality of new snow
  • Lack of an overnight freeze and 5000ft temperatures near 60F Thursday
  • Intensity and duration of the sun this time of year

We have a significant amount of uncertainty about how this day will play out. Don’t box yourself in by choosing routes that require you to travel through avalanche terrain to exit. As the warm temperatures increase our uncertainty grows and so does the potential for larger and more deadly avalanches. 

 A shallow, patchy snowpack exists in the southern and eastern areas of the zone, even on shady northern aspects. Some southern slopes are snow-free up to 5700ft. Use extra caution in these lower elevations where obstacles may be lurking just under the new snow, and creek holes may become drifted over or hidden.

Regions covered