Bulletin d’avalanche

Purcells

Dec 27 – 28, 2014Avalanche Canada
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Archivé · expiré 12 years ago

Danger d’avalanche

Mon
Tue
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Points saillants

A persistent weak layer of buried surface hoar is the sliding layer for human triggered avalanches. This problem results in the avalanche danger staying up at Considerable for the forecast period.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–4
    Thin windslabs and recent storm slabs may be sitting on a weak layer of surface hoar and/or a crust. This problem may persist through the Holiday season.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    3–6
    Shallow snowpack areas may continue to have concerns for deeply buried crusts with facets at the interface.  Large triggers like storm slab avalanches in motion may step down to near the ground where this problem exists.

Weather Forecast

Flurries or light snow is expected to continue overnight and during the day on Sunday with total accumulations around 5 cm combined with light winds and alpine temperatures around -15. Gradually clearing skies during the day on Monday as cold arctic air moves in from the North and alpine temperatures drop down to about -25. Continued cold and clear on Tuesday.

Avalanche Summary

No natural avalanches reported. Explosives control work resulted in avalanches up to size 2.5 that appear to have run on the mid-December surface hoar that is buried down 40-60 cm.

Confidence

Fair - Forecast snowfall amounts are uncertain

Snowpack Summary

Storm snow totals 30-70 cm above a very touchy surface hoar layer that was buried mid-December. Below 2100 m this storm slab sits on a thick, solid crust/ surface hoar combo and has been acting as the perfect sliding layer. This persistent slab remains touchy to the weight of a skier or rider, especially in wind effected areas. A hard rain crust with facets from early November is buried over 1 m down and has recently been reactive with larger loads (explosives and smaller avalanches) especially in the Northern part of the region where the snowpack is thinner.

Régions couvertes