Bulletin d’avalanche

South Columbia

Dec 19, 2017Avalanche Canada
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Archivé · expiré 9 years ago

Danger d’avalanche

Wed
Thu
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Points saillants

Snow amounts will continue to gradually accumulate over a variety of potential weak layers in the coming days. 

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    Recent west and northwest winds have created wind slabs in the lee of terrain features.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    As the recent new snow settles over the next few days, expect it to become reactive to human triggering where it may be sitting on a layer of feathery surface hoar crystals (sheltered areas at and below tree line or northerly alpine aspects)

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Wednesday

Weather Forecast

TUESDAY: Mainly cloudy with periods of snow in the afternoon and overnight, accumulations 10-20cm / wind moderate east / alpine temperature -11 WEDNESDAY: Cloudy with sunny breaks and isolated flurries / wind light northeast / alpine temperatures -12 THURSDAY: Mainly cloudy with isolated flurries / wind light to moderate northwest / alpine temperature -8

Avalanche Summary

Recent reports indicate explosives controlled and natural storm snow avalanches to size 2.5 in the alpine and tree line .As snow accumulates and settles in the coming days expect to see an increase in avalanche activity.

Snowpack Summary

The 20-40 cm of new snow accumulating through the weekend now sits on a wide variety of old surfaces including large surface hoar (weak, feather-like crystals), hard crusts formed by sun or wind, and sugary facets. As the snow load builds and slab properties develop, it will be important to monitor how the new snow is bonding to the old surfaces. Most concerning would be areas that have surface hoar sitting on top of a hard crust. A crust which was formed by rain in late November is a major feature in the snowpack and is down approximately 60-80cm at tree line elevations. Snowpack tests suggest the snow above is currently bonding well to it. Snowpack depth decreases rapidly below tree line. Look out for early season hazards such as rocks, stumps, and open creeks.

Régions couvertes