Bulletin d’avalanche

South Columbia

Jan 11 – 12, 2013Avalanche Canada
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Archivé · expiré 14 years ago

Danger d’avalanche

Sun
Mon
Alpin
2 · Modéré
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué

Points saillants

Conditions will be tricky to manage this weekend, as a touchy surface hoar layer is buried only on some slopes and not others. Make constant snowpack assessments as you travel and take a cautious approach to terrain selection.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–5
    Wind slabs have formed behind terrain breaks such as ridges and ribs. These could be triggered by the weight of a person or snowmobile.
  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–6
    Storm snow is particularly reactive where it overlies buried surface hoar. This weakness may be triggered from a distance and avalanches could be surprisingly large.

Confidence

Fair - Due to variable snowpack conditions

Weather Forecast

Saturday: Light W wind. Alpine temperature near -14. No snow.Sunday: Light N wind. Alpine temperature near -15. No snow.Monday: Light NW wind. Alpine temperature near -8. Light snow.

Avalanche Summary

A natural cycle of size 1-3 storm slabs occurred over the last few days. Skiers also several avalanches up to size 2, failing on buried surface hoar or facets. We are now moving into a period when natural activity is likely to decrease, but human-triggering will remain a concern.

Snowpack Summary

50-90 cm of recent snow is settling into slabs above old snow surfaces including surface hoar (found especially at and below treeline in sheltered areas), a sun crust (on steep S to SW-facing slopes) and facets. The distribution of buried surface hoar is patchy, but where it does exist, it is touchy, with widespread propagation and remote-triggering occurring. Recent winds have left wind slabs in the lee of terrain breaks such as ridges and ribs at alpine and treeline elevations. In areas sheltered from the wind, fast-moving sluff could throw you off your feet or carry you into a terrain trap. A strong mid-pack overlies a weak facet/crust layer near the base of the snowpack, which is now considered inactive.

Régions couvertes