Bulletin d’avalanche

South Rockies

Jan 20, 2017Avalanche Canada
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Archivé · expiré 10 years ago

Danger d’avalanche

Fri
Sat
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Points saillants

The shallow weak snowpack continues to be a concern for triggering large avalanches.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2
    Recent flurries and winds have formed fresh wind slabs. Wind slab avalanches in motion may step down and trigger deep persistent slab avalanches.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3
    Triggering deeper weak layers will remain possible with warm temperatures and wind loading.

Avalanche Summary

On Thursday, avalanche reports were limited to a size 1 skier triggered wind slab on a steep convex below treeline feature. We continue to be concerned about triggering the weak faceted layers in the snowpack, and our uncertainty revolves around what type of loading or weak spots are required for human triggering.

Confidence

Moderate - Wind speed and direction is uncertain

Weather Forecast

FRIDAY: Cloudy with sunny periods, moderate west winds easing throughout the day, freezing level around 1200 m.SATURDAY: Mix of sun and cloud, light southwest winds, freezing level around 1000 m.SUNDAY: Cloudy with isolated flurries, light south winds, freezing level around 800 m.

Snowpack Summary

Recent flurries and winds have formed thin wind slabs on lee features in exposed terrain at all elevations. The lower snowpack is quite variable throughout the region and the structure depends on snow depth. In deeper snowpack areas, the snowpack appears to be well settled and right side up with isolated concerns about the mid-December facet layer buried 50 to 100 cm deep. In shallow snowpack areas and lower elevations, the snowpack is heavily faceted. If a persistent slab is triggered from thinner snowpack areas it may release on basal facets resulting in a full depth avalanche.

Régions couvertes