Bulletin d’avalanche

Snoqualmie Pass

Northwest Avalanche Center
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Danger d’avalanche

Sat
Alpin
1 · Faible
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré 5 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Make observations as you travel and prepare yourself to adapt to the rapidly changing conditions. Mild temperatures and sunshine will try to cause the snow surfaces to become wet and unstable on all but the highest slopes. When you find sticky or punchy snow, it’s time to seek out firmer or lower angled terrain

Problèmes avalancheux

  • Loose Wet

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

    A strong April sun will drive the possibility for loose wet avalanches in locations where you find fewer clouds. Pay attention to the snow surface as you travel. When you begin to sink in past your ankle, encounter wet punchy snow, or see new rollerballs, it’s time to change slopes. Seek out slightly more frozen aspects or lower angled terrain. Even though loose wet slides can seem very predictable, don’t let them catch you off guard in higher consequence areas such as above a cliff or creek. 

    Competing weather factors will attempt to impact the snow surface Friday. A decent overnight freeze, cooling winds, and clouds should help the snow remain strong. The cloudiest conditions are expected later in the day and along the western half of the zone. However, we think the mild temperatures and sunshine will cause the surface to weaken in all but the cloudiest locations. Expect avalanche hazard to develop on easterly aspects in the morning before spreading to other slopes as the day continues. You’ll need to constantly make observations as you travel and adapt to changing conditions. At upper elevations, colder temperatures and a cool breeze should help the surface stay firm and limit the potential for loose wet avalanches.

    (4/1/2021) Small natural loose wet avalanches on Kendall Peak. These slides likely occurred 3/30-31. SW 5400'

Avalanche Discussion

Several warm sunny days resulted in natural loose wet avalanches around the Pass. This activity was not very widespread and generally remained small. Due to the recent weather, a variety of snow surfaces formed. Slopes facing E-S-W underwent the most significant melt-freeze process. However, you’ll notice the effects of the sunshine and warm temperatures on all but the higher due north facing features. 

Despite the recent spring-like weather the snowpack at mid and upper elevations has not transitioned. You can still find distinct layers. Large triggers such as collapsing cornices and loose slides could trigger isolated slabs in very rocky or wind-loaded pockets. 

As we make the move into spring, cornices and glide avalanches sit front and center in our minds. You may notice looming waves of snow on the ridgelines or see crevasse-like glide cracks in the snow. Predicting when these features may fail is incredibly difficult. So, choose routes that limit the time you spend near and underneath these springtime hazards. 

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

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