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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Out of date — this forecast expired 2 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Small human-triggered avalanches will become more possible on steep, sun-exposed slopes as the day heats up. While wet snow instabilities will be more widespread, a rogue wind slab in steep alpine terrain could be an unpleasant surprise. Continue to be alert for lingering unstable pockets of wind drifted snow and move to shadier slopes if the snowpack becomes wet and unsupportable. 

Avalanche problems

  • Loose Wet

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

    A warmer and sunnier day may reinvigorate wet snow instabilities as warm temperatures break down the surface crust. Look for these wet snow instabilities during the late morning or afternoon hours on W-SW-S-SE aspects. You’ll most commonly find these signs of warming on steep solar slopes near rock or cliff bands. While most of these slides would be small, don’t underestimate wet snow in bigger terrain where a small avalanche could push you into unwanted terrain. Consider moving to shadier terrain or to scoured surfaces if you notice rollerballs shedding or if you’re sinking past your ankles in wet, mushy snow. 

    (3/21/2021)

    Wet loose avalanches often initiate where snow sheds off rocks and trees onto the slope below. Note that there are both small rollerballs and wet loose avalanches in this image. 

    Photo: Zack McGill - Cascade Mtn Ascents

  • Wind Slabs

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

    Most wind slabs are well-aged and likely becoming harder to trigger as time passes. However, that may not be the case in all areas, especially if a stiff slab rests over weaker grains or a slick crust. Look for these slabs to linger on the leeward sides of ridges, beneath cornices, or in craggy alpine terrain. You can reduce your risk of an unpleasant surprise by assessing these slabs and looking for a poor bond to the pre-existing surface. Shooting cracks and snowpack collapses are signs that you found an unstable slab. 

    (2/23/2024)

    Wind etched surfaces like this are clues that wind slabs may exist nearby.

    Photo: Matt Primomo

Avalanche Discussion

We dropped the persistent slab problem that lingered for over a week in the East South zone. You can still find the buried surface hoar on most aspects above 6000 ft in the Ahtanum area, but no avalanche activity in over 7 days has us thinking that triggering an avalanche on this layer has now trended unlikely. Larger columns are also no longer producing propagating test results on the Jan 1st surface hoar. 

High pressure is slowly faceting out the upper snowpack. While this weak snow and a decomposing crust are unlikely to produce avalanches right now, it will be something to track as we start getting precipitation again.

Travel conditions are challenging across the forecast zone. Conditions will vary from drainage to drainage, so come equipped for firm surfaces and give yourself extra time to navigate these potential hazards. 

If you head out, let us know what you see by submitting a public observation

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