Bulletin d’avalanche

West Slopes Central

Northwest Avalanche Center
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Danger d’avalanche

Tue
Alpin
2 · Modéré
Limite forestière
1 · Faible
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

Wind drifting will continue and new and old wind deposits could avalanche with a human trigger. Expect to find deposits in unusual places, as several backcountry travellers have been surprised by triggering avalanches throughout the Cascades in the last few days. Avoid wind-affected snow on steep slopes on Monday.

Problèmes avalancheux

  • Wind Slabs

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

    A few observations have come in from the West Central zone, and all have reported finding wind-affected snow (observation, observation). In neighboring zones over the weekend, people triggered avalanches, and one person was caught on Ruby Mountain, just north of the West Central boundary on Saturday (observation). We're glad the person was unharmed. 

    Avalanche danger is Moderate at upper elevations, which means human-triggered avalanches are possible. We have unusual wind right now, which has distributed wind slabs in unusual locations and is catching people by surprise. Slabs have been tricky to identify with distribution and how reactive they are. Search for textured, wind-affected surfaces and feel for stiffer snow. Search for active wind loading and avoid affected slopes. Long, shooting cracks from your weight are obvious indicators of a weak snowpack.  

    Assess snow conditions before committing to a steep slope. Changes in snow conditions may be abrupt. The amount of snow available for transport has dissipated, and slabs may be more difficult to trigger than in the previous few days. We suspect new slabs will likely be less than a foot deep. Continue to avoid wind-loaded slopes greater than 35°.

    (2/17/2024) A small, natural avalanche slab avalanche found at 6000ft in the neighboring West North zone. Photo: Matt M

Avalanche Discussion

A few avalanches in neighboring zones have failed deeper than expected, on weak layers above the Early February Crust or within the newer snow layer above the crust, which is about 1 1/2ft deep. We're not sure how widespread  this problem is, but it may cause avalanches to be larger and wider than expected if you trigger one. They would probably occur in the same location as our wind slab concerns, so keep on avoiding wind slabs on steep slopes to avoid this concern too. 

We'll probably get a dusting of snow on Monday, which won't be enough to change the avalanche danger. Thin snow cover, bare patches, and crusts exist at lower elevations. Many unexpected holes are present in the snow at lower and mid elevations as well. If you make it into the backcountry, send us an observation so you can help contribute to better forecasts in the zone!

Régions couvertes