Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Significant rain and high-elevation snow just impacted the zone over the weekend. But avalanches are still possible in some lingering spots. To avoid triggering an avalanche, steer around steep unsupported slopes, and convex rolls at higher elevations and move to lower angle slopes if you're sinking deeply into heavy, wet snow. 

Avalanche problems

  • Loose Wet

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

    Temperatures are forecasted to cool slightly, but we probably aren't putting the snowpack into a solid freeze. You might trigger some small, wet loose avalanches at lower elevations in steeper terrain. Even though the sun is not very strong this time of the year, it may become the tipping point with the mild temperatures. Even smaller wet avalanches might be strong enough to knock you over or push you into trees and rocks. Be aware of the instability, and consider moving to lower-angle slopes if you're sinking deeply into wet heavy snow. 

    (12/10/2023)

    Example of a small wet loose avalanche. 

    Photo: Matt Primomo

  • Storm Slabs

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

    Upper elevations likely stayed as snow, and you could still trigger an avalanche in the new snow. The likelihood of triggering an avalanche is decreasing, but cautious travel is still necessary at these upper elevations. We don't have a lot of info on how well the new snow bonded with the underlying crust, so use quick hand pits and small, steep test slopes to see how easily the new snow slides on the crust. If it slides off easily, that's a good sign avalanches are more likely.Slopes over 35 degrees, convex rolls, and areas exposed to the wind are the most suspect spots to trigger an avalanche. Steady winds drifted the snow into deeper slabs, so be particularly cautious to avoid steep slopes below ridgelines. Look for signs of unstable snow, like cracks that shoot away from you or other recent avalanches.

    (12/1/2023)

    Small test slopes like this can be great indicators of unstable storm slabs. 

    Photo: Matt Primomo

Avalanche Discussion

The East South received around 2" of water during the weekend's storm. The bulk of that precipitation likely fell as rain at lower elevations, while upper elevations could have over 2ft of new snow. After a big storm or rapid change in conditions, we have increased uncertainty on how the new snow reacts and how well it bonded to the old snow surface. When there is more uncertainty, it's also always a good idea to step into new terrain slowly. Don't commit to larger slopes before first seeing how the snow reacts on many small, lower-consequence slopes. As you travel, you should carefully observe how well the new snow bonds to the underlying surface. 

Joe Dellaporta got out into the East South on Saturday. While we had hopes of snowmobiling out of the lower elevation snowparks, there is a lot of bare ground from last weekend's atmospheric river. He did find significantly more snow as you travel west in the zone and get closer to the crest. There was over a foot of snow at 3500ft near the HWY410 closure and just 10 inches further east near Bumping Lake. Ahtanum Meadows Snowpark is bare ground.

The good news is that it began snowing hard in East South around midday on Saturday. Let's hope some of that snow survives this next round of rain. But for the moment, depending on where you go, the chance to hit buried rocks, logs, and other obstacles may still be a significant hazard. 

We don't have much for on-the-ground observations of East South. So, if you're out enjoying the new snow, let us know what you see by submitting an observation.

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