Bulletin d’avalanche

South Columbia

Dec 30 – 31, 2013Avalanche Canada
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Archivé · expiré 13 years ago

Danger d’avalanche

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

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    New snow combined with moderate to strong southwest and northwest winds have created wind slabs in the lee of terrain features on a variety of aspects.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    3–5
    Buried persistent weak layers exist in the upper 110 cm of the snowpack.

Confidence

Good

Weather Forecast

Tuesday: Dry, mostly cloudy with some sunny breaks. Treeline temperature around -3C. Ridgetop winds aronud 35 km/h from the W or NW.Wednesday: Dry, cloudy with some sunny periods. Temperatures starting cold but rising to around -3C in the afternoon. Winds around 30 km/h from the NW.Thursday:  Precipitation becoming steadily heavier through the day. 5-10 cm expected. Temperatures rising in the afternoon to around -1C. SW winds up to 80 km/h.

Avalanche Summary

A few slab and loose avalanches to size 1.5 have been reported in the last 2-3 days. These are isolated to the most recent storm snow.

Snowpack Summary

Recent moderate to strong southwesterly and northwesterly winds continue to build wind slabs on exposed alpine and treeline slopes. 30-50 cm of recent storm snow sits on a weak layer consisting of surface hoar crystals, stellar crystals and/or crust. Around 60-90 cm below the snow surface, the early December surface hoar, facetted snow, and/or a crust interface sits and is reportedly still variably reactive in snowpack tests.The late-November persistent weak layer consists of a sun crust on steep south facing slopes and surface hoar in sheltered areas. It is now buried 80-110cm below the surface. Snowpack tests vary on this interface with some results producing "sudden" shears and others producing no results. This interface is generally considered to be dormant. However, professional operators are still keeping a close eye on it.A weak layer of facets sitting on a crust that formed in October, sits near the base of the snowpack. This layer is predominantly found on north-facing alpine slopes with smooth ground cover. Triggering this weakness is unlikely, however if triggered the resulting avalanche would potentially be a large event with high consequences.

Régions couvertes