Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

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

Up to 1 foot of new snow accumulated through Friday, and you can still trigger avalanches in the new snow, particularly where the wind drifted snow into stiffer slabs. Avoid steep terrain if you observe signs of instability, such as recent avalanches or long shooting cracks. As temperatures warm and the sky clears in the afternoon, wet avalanches may also run at lower elevations.

Avalanche problems

  • Storm Slabs

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

    We have limited observations and a fair amount of uncertainty, but with up to a foot of new snow, you could trigger storm slabs in steep terrain. Avoid likely trigger points such as convex rolls, the base of cliffs, and steep open slopes. Also, pay attention to warning signs of instability, such as shooting cracks or recent avalanches. You can make observations as you travel using small test slopes and quick hand pits to assess how the new snow reacts. Snow that slides easily in a cohesive block indicates that triggering an avalanche is possible. 

    Avalanches may be larger and easier to trigger where the wind drifted snow into stiffer slabs. Use visual clues such as textured surfaces, deep pillowlike drifts, or feel for stiff over soft snow layering to identify likely wind slab locations. Avoid steep slopes and potential trigger spots such as the base of cliffs and below corniced ridges. 

    (1/9/2023)

    Storm slabs like this example are likely on Friday. Avoid common trigger spots, like the base of cliffs.

    Photo: Willie Webster

  • Loose Wet

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

    Temperatures will be a notch warmer on Saturday, and there is a good chance of some afternoon sun breaks. With this combination, you may see wet avalanches as the fresh snow warms up and becomes heavy and saturated. These avalanches tend to start with trees or cliffs shedding snow onto steep slopes, but you can also trigger these avalanches while skiing. Pay attention to overhead hazards and avoid getting caught in your sluff in steep consequential terrain. Wet loose avalanches may be possible on all aspects at lower elevations, but you're most likely to see these avalanches run on sunny slopes at upper elevations. Move to shady terrain or lower-angle slopes if the snow becomes heavy and wet or you start to see rollerballs on steep slopes.

    (3/10/2023)

    Wet loose avalanches like this one will become more likely with daytime warming on Saturday. 

    Photo: Matt Primomo

Avalanche Discussion

The East-South zone continues to be in a favorable pattern for daily snowfall. Thursday night's storm brought a healthy 10-12 inches of new snow to favored areas in the southern portion of the zone. Areas further north received 4-6 inches of snow. Our observations for this storm are limited to areas in surrounding zones, so we are quite uncertain of the reactivity of the new snow. We expect you will most likely find unstable snow on very steep terrain or wind-loaded slopes. However, with minimal information, approach terrain with an assessment mindset and be prepared to dial back slope angles if you see signs of instability.

If you ventured out to enjoy the new snow, please take a moment to use our observation platform and let us know what you saw.

I was last in the Ahtanum Meadows area on February 28th, and I found 7-12 inches of new snow over the most recent crust from Valentine's Day. There was some weak snow below the Valentine's Crust, but snowpack tests yielded unremarkable results. This crust and the associated weaker snow are likely now 2-3ft below the snow surface. While we expect most avalanches to involve just the recent snow, we are still tracking this deeply buried interface as storms incrementally load it. So far, we don't expect avalanches on this layer, but we'll continue to monitor this interface.

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