Bulletin d’avalanche

East Slopes South

Northwest Avalanche Center
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Danger d’avalanche

Mon
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 6 months ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

It is unlikely, but not impossible, to trigger a large and surprising slab avalanche, especially in terrain that has been wind-affected. You can reduce your risk by choosing more sheltered terrain or smaller, simpler slopes. Also, keep tabs on how wet and weak the snow surface is, and don't linger under large, looming blocks of snow at ridgelines.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    1–2

    You can find buried weak layers 1-3 feet down that show some signs of healing, but we can't say for sure with much confidence, given the lack of data. Also, we suspect the warm up this weekend is maintaining some possibility of triggering an avalanche. If water works its way down to buried weak layers, this could reinvigorate instability by the end of the day. Cornice fall could be an issue as things warm up, and a big trigger like this might be just what it takes to let loose a deadly avalanche. All in all, the most suspect place you'd still trigger a slide is in exposed wind-loaded terrain, and weak layers can be buried even deeper here, too. 

    This problem is tricky to manage in the backcountry. If you plan to travel near a neighboring forecast zone, consider reading that forecast as well to equip your toolbelt with more information, given the limited data for East South. Either way, ease into steeper terrain and be thoughtful about the complexity and exposure of slopes you plan to ski or ride. You're unlikely to get clear feedback from the snowpack before triggering a large slide in consequential terrain. 

    (3/1/2026)

    A large avalanche triggered by a snowmobile rider last weekend in the zone. This happened on a NE aspect at 6700 ft.

    HS- AMu-R2-D2-O   

    Photo: Northwest Avalanche Center

Avalanche Discussion

The East South zone will largely be spared from rain impacting the rest of the forecast region through Sunday morning. Some dribbles may sneak over the Cascade Crest, however. The snowpack may just be mushy and pasted together. But if you find yourself getting rained on more heavily than forecasted, assume the increasing likelihood of being able to trigger a small wet loose avalanche. This may also increase the likelihood of a persistent slab avalanche.

The weak layers we've been tracking are the 2/13 buried surface hoar and facets around the 2/7 crust. These two layers are very close together and can often appear as a single, weak layer. An NWAC forecaster traveled to the Pinegrass Ridge area on Wednesday and identified these layers about 2 feet below the surface that produced propagating test results on west aspects. On southerly aspects, they found the layers gaining strength. The last (and only) known persistent slab avalanches that failed in the East South occurred on February 28th around Darland Mountain. In the nearby East Central zone, snow professionals have reported no notable snowpack test results associated with these layers for the last 3 days. 

NWAC Forecasters produce more accurate avalanche forecasts when the community chips in. Please let us know what you're seeing out there.

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