Bollettino valanghe

East Slopes South

Northwest Avalanche Center
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Pericolo valanghe

Tue
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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In sintesi

Winds will shift easterly on Monday, and shallow slabs of wind-drifted snow may form throughout the day. Higher elevation ridgelines and near the Cascade crest are the most likely place to trigger one of these avalanches. Watch for actively blowing snow and pillow-like drifts to identify and avoid potentially unstable slopes in steep terrain.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    A switch to easterly winds on Monday will likely form fresh wind slabs on different aspects from over the weekend. While older wind slabs are likely stubborn, these new slabs will be small but more sensitive and easier to trigger. These new wind slabs should be easy to identify and avoid using visual clues such as actively drifting snow or deeper drifts. High-elevation alpine ridges, confined terrain features, and the base of cliffs are likely locations to trigger a wind slab. If you see signs of instability, such as shooting cracks, move to lower-angle slopes or more sheltered terrain. While we expect the size of these avalanches to be small, don't let your guard down in extreme terrain where getting knocked off your feet could have dire consequences.

    (3/6/2023)

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

    Photo: Joe Dellaporta

Avalanche Discussion

This past week hasn't produced much precipitation in the eastern part of the Cascades. Instead, 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 recent winds also left wind-packed snow, stiff slabs, and scoured slopes in many locations.

Except for due north, most aspects below 5000ft have a stout crust from the previous sunny weather. Another sunny, mild day is in the forecast for tomorrow. Each consecutive day of sun thickens these crusts a little more, and with a good overnight refreeze, the potential for wet loose avalanches decreases a little bit each day. You still may see some small wet avalanches tomorrow, particularly at lower elevations, but they will likely be limited in size and distribution. Since these avalanches tend to start from steep rocks and cliffs warming in the sun, watch for these overhead hazards and move onto shadier terrain if you can easily get wet, heavy snow sliding downhill. 

Some of the days this past week have certainly felt like spring. However, beneath the surface, a mid-winter snowpack that is deep and layered 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.

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