Bulletin d’avalanche

East Slopes North

Northwest Avalanche Center
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Danger d’avalanche

Mon
Alpin
2 · Modéré
Limite forestière
1 · Faible
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 4 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

You could trigger small avalanches where the wind drifts snow near high elevation ridges. Expect light snow with stormy conditions intensifying near dusk. The avalanche danger will increase sharply on Sunday night.

Problèmes avalancheux

  • Wind Slabs

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

    You may be able to trigger small avalanches in wind-drifted slabs on leeward sides of ridges at the highest elevations. Snow accumulation and drifts will slowly build by the afternoon. Check for warning signs such as stiffer, deeper snow, shooting cracks, and active wind transport. Steer around steeper slopes holding thicker drifts of snow. Any slabs will likely be localized and small. If you trigger an avalanche, it could be big enough to be dangerous where it could push you into rocks, cliffs, or trees.

    (3/31/2022) A recent example from the Stevens Pass zone. A small slab avalanche was triggered in a shallow, cross-loaded pocket of snow. Photo: Josh Hirshberg

Avalanche Discussion

Since midweek, snow showers brought light accumulation near and west of Washington Pass. New snow through Sunday afternoon along with strong southerly winds will be enough for a slight increase in avalanche danger. Snowfall should intensify around dark with a dramatic increase in danger overnight and into Monday.

The spring road clearing operation on North Cascades Highway, SR 20 is currently underway midweek. The road is likely gated at Silver Star milepost 171. With access becoming limited and professional operations in the area closing for the season, your observations are as important as ever. If you're in the mountains, let us know what you see. 

A widespread natural wet loose avalanche cycle occurred last weak in the Washington Pass vicinity.  While recent avalanche activity centered on wet snow avalanches, there's still some winter-like layering to keep tabs on. On wind-sheltered NW-NE aspects near and above treeline, observers found near-surface facets 1-2 feet below the surface and often above a crust. This weak snow layer was involved with persistent slab avalanches near the Mount Baker ski area and other parts of the Cascades. A deeper persistent weak layer still exists in the zone that was responsible for avalanches in early March. You can find the layer about 3 feet deep, sandwiched between eroding crusts on NW-NE aspects near and above treeline. This could be a culprit for wet slab avalanches later in the spring. When warm temperatures warm again and melt the snow, watch for when this layer becomes wet and weak. 

Régions couvertes