Bulletin d’avalanche

East Slopes South

Northwest Avalanche Center
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Danger d’avalanche

Wed
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 3 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

An easterly wind event will bring light snow and build stiff slabs of wind-drifted snow where you could trigger an avalanche. Most avalanches will likely be small but could form on weak or slick surfaces and be sensitive to triggers. Look for actively blowing snow and textured drifts as a way to identify and avoid these wind-loaded slopes.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–1.5

    Winds picked up and switched to easterly on Monday afternoon. While there isn't much snow available for transport, a few inches of snow during the day and the soft snow lingering on northern aspects will drift around into wind slabs. These fresh wind slabs will form over various surfaces, including slick crusts and weak, faceted snow, so they could be quite sensitive to triggering. While none of these avalanches are likely to be large, don't let your guard down in terrain where getting knocked off your feet could have significant consequences. Alpine terrain with steep, confined features and cliffs is the most likely place to encounter wind slab problems. But small wind slabs could also form near ridges at lower elevations. Look for actively drifting snow, textured surfaces, and "fat" looking drifts to identify steep slopes to avoid. Warning signs such as shooting cracks are bullseye evidence that the snow is unstable. 

    (3/6/2023)

    Shooting cracks, like in this example, is a sign that you could trigger a wind slab. 

    Photo: Joe Dellaporta

Avalanche Discussion

Some days this past week have felt like spring, but you should prepare for a return to winter with some fresh snow in the forecast. Over the previous week, we have seen a decent bit of wind and quite a lot of sunshine. Other than isolated reports of small wind slabs and wet loose avalanches, there also hasn't been much avalanche activity or other signs of unstable snow. Southern aspects and lower elevations have thick crusts on the surface in most locations, while true north aspects still hold soft, recycled powder that is beginning to weaken and become faceted. The winds also left wind-packed snow, stiff slabs, and scoured slopes in many locations.

At mid and upper elevations, a deep and layered winter snowpack exists. If you dig down, you will find older layers of melt-freeze crusts from around Christmas, MLK, and Valentine's day. These layers are not a concern for avalanches at this time but are a reminder that we have not transitioned to a spring snowpack quite yet. For more information about the deeper snowpack, check out my observation from Ahtanum Meadows this past week.

Régions couvertes