Bulletin d’avalanche

Northwest Coastal

Feb 7 – 8, 2014Avalanche Canada
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Archivé · expiré 13 years ago

Danger d’avalanche

Sun
Mon
Alpin
1 · Faible
Limite forestière
1 · Faible
Sous la limite
1 · Faible

Points saillants

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1–2
    Isolated fresh thin pockets of hard and soft wind slabs may be lurking below ridge crests and behind terrain features in exposed terrain.
  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1–4
    Cornices are becoming undermined and brittle. A hazard in themselves, but also as a heavy trigger for slab avalanches on the slope below.
  • Loose Dry

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1
    The faceted powder is sluffing easily with human-triggers on steep sheltered slopes.

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain on Monday

Weather Forecast

Saturday: Mainly sunny. Light alpine wind with strong outflow wind likely valleys. Freezing level at valley bottom with alpine temperature reaching -15 C. Sunday: Sunny with cloudy periods. Light alpine wind. Freezing level at valley bottom with alpine temperature reaching -13 C. Monday: Increasing cloud with light snow possible in the afternoon.

Avalanche Summary

Reports from Thursday include natural and artificially triggered cornice falls to Size 2.5 with only 1 Size 1 wind slab triggered on the slope below. The faceted surface snow is also sluffing readily in steep terrain with skier traffic.

Snowpack Summary

A highly variable snow surface includes surface facets, surface hoar, thin wind slabs, and scoured crust, or any combination thereof. Remember to take stock of current surface conditions if you're out in the mountains. Once buried by a cohesive slab, surface hoar or a thin layer of facets sitting on a crust almost always becomes a weak layer, and will often persist.In sheltered areas, large surface hoar is growing on approximately 10cm of faceted old storm snow sitting on the late January crust, which is likely faceted and laminated and could have surface hoar on top. The entire snowpack is likely faceting to some degree, especially where it is shallow. Basal facets and depth hoar are likely, but triggering is only a concern in thin and variable snowpack areas with large triggers.

Régions couvertes