Bulletin d’avalanche

South Columbia

Apr 17 – 18, 2013Avalanche Canada
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Archivé · expiré 13 years ago

Danger d’avalanche

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

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–4
    Forecast snow and wind will likely build new wind slab problems at treeline and above. Large looming cornices exist on ridgelines and pose a threat to slopes below.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1–6
    A weak interface buried down about 60-120 cm has been creating surprisingly large avalanches in neighboring regions. Additional loading by snow and wind may bring the slab above this layer closer to its tipping point.

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain

Weather Forecast

Two approaching frontal systems will bring warm, wet and windy weather through the forecast period. Thursday: Overcast. Moderate precipitation amounts. Ridgetop winds moderate from the NW. Freezing levels rising to 1900 m. Friday: Overcast. Light-moderate precipitation amounts. Ridgetop winds moderate from the West. Freezing levels 1700 m. Saturday: Overcast. Light precipitation amounts. Ridgetop winds moderate to strong from the West. Freezing levels 1500 m and falling to valley bottom overnight.

Avalanche Summary

On Tuesday, a couple of large, older (past 48hrs) slab avalanches size 2-3 were spotted from the flanks of Albert Peak. Crown depths were approximately 50 cm deep and the suspect failure plane may have been the early April surface hoar. Loose wet natural avalanche activity also occurred on solar aspects up to size 1.5. In neighboring Glacier National Park, skiers triggered a size 3 slab on a buried crust on an east aspect in the alpine on Monday. Last Sunday, a naturally triggered size 2.5 slab failed on a buried crust.  With forecast snow and wind this interface may be reaching it's tipping point.

Snowpack Summary

Forecast snow and wind will likely build new wind slabs at treeline and above. Cornices are very large and pose a threat to slopes below.A weak interface down about 60-120 cm consists of a crust on solar aspects, and surface hoar on high-elevation northerly aspects. Recently, very large avalanches occurred in this region and in the neighboring Glacier National Park.  The slab above this interface may be reaching tipping point with additional loading.

Régions couvertes