Bulletin d’avalanche

South Rockies

Jan 6 – 7, 2015Avalanche Canada
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Archivé · expiré 12 years ago

Danger d’avalanche

Thu
Fri
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Points saillants

Watch for fresh wind slab formation in wind exposed terrain.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    Moderate to strong south/southwest winds Wednesday will likely form fresh and potentially reactive wind slabs. Watch for triggering in the lee of ridge crests and terrain breaks.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–4
    A crust which formed in December should remain on your radar as it has the potential to produce large avalanches. Dig down and test weak layers before committing to a line.

Confidence

Fair

Weather Forecast

Synopsis: A battle between unseasonably mild Pacific air and cold air from the Arctic is underway Wednesday. The models are showing conflicting outcomes, but my best guess says the freezing level should remain near Valley Bottom. Confidence in the weather forecast is POOR. Wednesday: Freezing Level: Valley Bottom; Precipitation: Nil; Wind: Treeline: Moderate, SW | Ridgetop: Strong, W.Thursday: Freezing Level: Valley Bottom; Precipitation: Nil; Wind: Treeline: Light, Variable | Ridgetop: Light, W.Friday: Freezing Level: Valley Bottom; Precipitation: Nil; Wind: Treeline: Light, Variable | Ridgetop: Moderate, NW.

Avalanche Summary

Some surface sluffing was reported to have occurred in sheltered treeline areas on Monday. At higher elevations generally small wind slabs were also reported.

Snowpack Summary

Up to 19cm of recent snowfall has been shifted into wind slabs in upper elevation terrain by moderate to strong westerly winds. These new accumulations overlie hard wind slabs in exposed terrain, and low density faceted snow in sheltered areas. Up to 75 cm below the surface you will likely find a hard, thick crust which formed mid-December. This crust has overlying facets and surface hoar (up to 10 mm in sheltered locations at treeline and below). This layer seems variably reactive throughout the region. In areas where the overlying slab is thick and cohesive, large avalanches are possible at this interface. A crust/facet combo which formed in November seems to have gone dormant for the time being.

Régions couvertes