Bulletin d’avalanche

West Slopes South

Northwest Avalanche Center
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Danger d’avalanche

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

Points saillants

We’re several days out from the last big storm and wind event. If you’re going to trigger an avalanche, it will likely be in a lingering pocket of wind-loaded snow at upper elevations. Be leery of firm pillow-like drifts especially above rocks and cliffs.

Problèmes avalancheux

  • Wind Slabs

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

    Finding wind-affected snow might be easy. The trick will be figuring out if one of these lingering wind slabs can fail and produce an avalanche. Start with your eyes. Look for firmer, textured surfaces and deeper pillow-like drifts. You’re most likely to find them along exposed ridges, in the tops of chutes, or below cliffs. If you find one on a smaller test slope, see how it reacts to your weight. It might crack or even produce a tiny slide. Observations like this can indicate if wind slabs on similar aspects might still fail. It will be easiest to trigger one of these wind-loaded pockets in very steep terrain, on a convex rollover, or an unsupported slope. 

    Since we’re talking about wind slabs that may or may not fail, think about the consequences of being wrong. Would this slide carry you into rocks or trees? With so many obstacles, even small avalanches can result in rough, unforgiving rides. 

    (11/24/2024) A small skier triggered wind slab. This avalanche occurred in a pillow-like drift right  below ridgeline. Photo: Eddie R

Avalanche Discussion

Happy Thanksgiving!

After several weeks of stormy weather, things are quieting down . This past weekend's system brought 1-2 ft (30-60cm) of snow to much of the West South. In some places, soft snow still clings to very steep faces. With a bit more sunshine and some slightly warmer temperatures, this could result in a few natural loose avalanches shedding from rocky faces. We don’t expect large slides, but keep an eye on what’s above you, especially if you see snowballs falling off trees or cliffs. 

The last major avalanche cycle occurred on Sunday. WSDOT traveling near Chinook Pass Tuesday found two large natural avalanches from that cycle along the east side of Hwy 410 (6000ft, SE aspect). This adds to the numerous reports of natural and human-triggered storm and wind slab avalanches. The last known slides were a pair of small human-triggered wind slabs near Crystal Mt on Monday. Crystal Mt Ski Patrol tested several previously closed slopes with explosives Wednesday with no results. All this suggests, the snowpack is healing and avalanches becoming less likely. 

Even still, we have very limited information about the snowpack and it’s hard to say much with any certainty. What we do know is early-season conditions still exist. Rocks, trees, bushes, creeks, and logs abound. The snow depth increases significantly as you gain elevation. There are several crusts in the snowpack, but so far, we aren’t aware of any avalanches on these layers. 

Uphill travel at a closed ski resort: 1. Follow the ski area’s uphill travel policy. 2. Avalanche mitigation may not have occurred. You should approach the terrain as if it were any other backcountry slope. 3. Numerous other hazards may exist, including electrical lines, snowmaking, heavy machinery, and other motorized traffic. 4. Ski patrol and other ski area staff are not there to respond to emergencies. Travelers should be self-sufficient.

Régions couvertes