Bulletin d’avalanche

South Columbia

Jan 1 – 2, 2015Avalanche Canada
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Archivé · expiré 12 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

Conditions are variable across the region. Cautious route-finding and conservative decision-making are essential.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–4
    Recent strong northerly winds left wind slabs on lee slopes. These may become hidden by fresh snowfall, making them tricky to spot.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2–5
    A buried surface hoar/ crusts layer demands respect. It is easy to trigger persistent slabs, even from a distance.

Confidence

Fair

Weather Forecast

Snowfall is expected to increase overnight and into Friday (5-10 cm by Friday afternoon). Winds are forecast to be moderate from the SW to NW. Freezing level at valley bottom. Snowfall becomes light on Saturday before a second pulse of snow arrives late on Sunday.

Avalanche Summary

Persistent slabs continue to be triggered by skiers, vehicles and remote triggers (from a distance away). These have been up to size 2.5 and failing 50-70 cm down on the mid-December crust/surface hoar layer. Many of these have been around treeline elevation, although some smaller sized avalanches were triggered as low as 1750 m. Several size 1-1.5 wind slabs also failed naturally or with skier triggers following strong northerly winds.

Snowpack Summary

New snow may hide wind slabs which formed recently in response to strong northerly winds. The primary concern is the persistent weak layer of mid-December surface hoar. Below 2100 m this surface hoar sits on a thick, solid crust and has been acting as a perfect sliding layer. Fractures have been propagating long distances and have allowed for remote triggering from adjacent terrain. A hard rain crust with facets from early November is buried more than a metre down and is currently unreactive. However, triggering from shallow rocky and unsupported terrain remains a concern.

Régions couvertes