Lawinenlagebericht

East Slopes Central

Northwest Avalanche Center
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Lawinengefahr

Sun
Hochgebirge
2 · Mässig
Waldgrenze
1 · Gering
Unterhalb
1 · Gering
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Kernpunkte

You can trigger avalanches at upper elevations where winds are forming fresh slabs of snow. Large avalanches on an old, weak layer remain a concern in similar terrain. Plan to move away from steep slopes where you see active wind drifting near ridgelines.

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    Winds are expected to increase in the afternoon. With this, snow may begin drifting more readily at upper elevations. Shallow slabs may become possible to trigger on a variety of slopes, but may be most prominent just below ridgelines and cornices. The shallow slabs themselves may not present a major concern depending on the consequences of the terrain you are in,  but a small slab has the potential to step down and become wider than expected. 

    Use visual clues such as drifts around rocks or vegetation and textured surfaces to help you identify likely spots for wind slabs. Consider typically wind loaded terrain features, such as the leeward sides of ridgelines, alpine couloirs, gully features, and cross-loaded depressions. Dial it back if you notice shooting cracks, whumphs, or hollow-sounding snow. 

    (2/18/2024)

    Triggering a wind slab in the wrong spot could result in a much larger and wider avalanche if it breaks on old snow above the Early February Crust. 

    W aspect, 6200 ft in the Teanaway.

    Photo: Katie Warren

Avalanche Discussion

On February 22nd, a party of skiers in the Teanaway drainage triggered a slab avalanche on a layer of 1-2mm facets just above the early February crust. The large (D2) avalanche occurred near Longs Pass, 6,200ft, W was triggered from a lower-angle, 30-degree slope near a cluster of trees. A crack propagated uphill and across in both directions. The avalanche ran to either side of the lower-angle feature and didn't involve the party that triggered it. This close call may be a sight of things to come.

On Friday, observers in the Eight-mile Creek near the Stuart Range found freshly forming wind slab conditions. They were able to trigger small avalanches 2-6" deep in the drifted snow. We expect these wind-drifted slabs to grow in size on Saturday. They also reported wet avalanches that ran on Thursday and Friday on steep, sun-exposed slopes.

You may be able to trigger a slide on buried faceted layers above the Early February Crust, as it's still a prominent concern for upper elevation, wind-loaded terrain. In some areas, the bond with the stout Early February Crust (EFC) is favorable. Make observations as you travel, paying close attention to surface conditions. Stiff wind-textured surfaces can point you to potential wind slab locations, and wet snow surfaces indicate wet loose avalanches are possible. You can also use quick hand pits to feel stiff over soft snow and observe the bond with underlying crusts. When in doubt, reduce your uncertainty by choosing more supported and simpler terrain.

Since February 15th, 14 unintentionally human-triggered avalanches have failed on or just above the EFC throughout the Washington Cascades. The most recent was on the 22nd near Longs Pass. Most of these avalanches have been between 5000ft and 8000ft and cover all aspects. It has been a number of days since the last reported avalanche. Unfortunately, these problems can be tricky and linger in certain sub-ranges like the Wenatchee Mountains or near specific terrain features like steep, rocky slopes with a shallower snowpack. 

Your avalanche, snowpack, or weather observations are extremely valuable to the avalanche community. Help create a more accurate avalanche forecast by submitting your observations here.  

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