Bulletin d’avalanche

Kootenay Boundary

Jan 19 – 20, 2012Avalanche Canada
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Archivé · expiré 15 years ago

Danger d’avalanche

Sat
Sun
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Watch for increasingly stormy conditions starting Friday afternoon.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–3
    Shifting winds have set up soft wind slabs in a variety of areas on lee slopes in exposed areas. The warmer temperatures will help snow stick.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    1–4
    Storm slabs will become sensitive with warming temperatures and new snow, especially towards the end of Friday.

Confidence

Fair - Intensity of incoming weather is uncertain on Saturday

Weather Forecast

Friday: Mostly flurries during the day with heavier snowfall starting in the afternoon. Winds will be from the west, initially light, increasing through the day. The freezing level will rise to around 1000 m. Friday night: Significant accumulations of new snow - around 20 cm. Saturday: Further snow with another 10-15 cm likely. Strong southwesterly winds. Freezing level briefly going up to 1500 m, but cooling off rapidly by Saturday night. Sunday: light snow, freezing levels around 500 m.

Avalanche Summary

Ski cutting produced size 1 loose and occasional soft slab avalanches on Wednesday with minimal propagation. Widespread sluffing to size 1 was noted on Tuesday and Wednesday in the new snow on steep terrain.

Snowpack Summary

Average treeline snow depths are nudging over the 2 m mark in this region. In the last seven days, between 40 and 80cm of cold, low density snow has fallen in this region, which has settled to create a storm slab 20-40 cm thick. Cold temperatures have kept the snow light and cohesionless in most areas, although moderate winds have started to develop wind slabs on a variety of aspects. In some areas, the strongest winds have been at valley bottom, so don't discount the possibility of finding wind slabs in unusual places, at low elevation, in generally sheltered glades, that kind of thing. A crust now lies buried around 25-45 cm below the snow surface at elevations below 1900 m. Some areas reported this crust had a layer of surface hoar on it when it was buried. Occasional reports of small soft slab avalanches that have started to come in indicate this slab is starting to be become sufficiently cohesive to produce slab avalanches. There is a blog posting on the Forecaster Blog (link on the sidebar on the left) that discusses this issue in more depth. The mid-December surface hoar/facet persistent weakness, now down 70-120 cm, remains a concern only for very heavy triggers in thin slab areas.

Régions couvertes