Bulletin d’avalanche

North Columbia

Dec 25 – 26, 2022Avalanche Canada
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Archivé · expiré 4 years ago

Danger d’avalanche

Tue
Wed
Alpin
4 · Fort
Limite forestière
4 · Fort
Sous la limite
3 · Marqué

Points saillants

Accumulating snow and wind continue to produce slabs primed to avalanche.

Keep terrain choices conservative and give the snow time to settle.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2–3

    Two weak layers are buried at a prime depth for human triggering within the top metre of the snowpack. Most avalanches to date have released between 1700 and 2200 m. The likelihood of triggering these layers may increase this weekend as warm and stormy weather returns.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    1–2

    Fresh low density snow falling since Friday night is sitting on a variety of weak surfaces that were formed during this past week's cold spell.

    Southwest winds will have likely developed wind slabs and they will be thickest and touchiest in lee terrain features.

    A warming trend starting late Sunday will increase reactivity.

Confidence

Moderate

Avalanche Summary

Since early Saturday morning, there have been numerous reports and observations of widespread natural and human-triggered avalanche activity. This has been from storm slabs, wind slabs, and loose dry avalanches.

Snowpack Summary

Between Friday to Sunday morning, up to 60 cm of snow may have accumulated. Storm slabs are likely to form as the air temperature warms. The new snow may not bond well to the variety of surfaces that it overlays. These include hard wind-packed snow in exposed alpine, crust on steep sun-exposed slopes, small surface hoar crystals in wind-sheltered areas, and sugary facet crystals in other areas.

Numerous other problematic layers exist in the top 40 to 100 cm of the snowpack, consisting of surface hoar, faceted grains, and/or a crust. Avalanches have been most prominent between 1700 and 2200 m and on all aspects. Read our forecaster blog for managing a persistent slab problem.

Weather Summary

Saturday Night

Cloudy, 10 to 20 cm accumulation, 20 to 45 km/h southwest wind, treeline temperatures -8 °C.

Sunday

Cloudy, 5 to 10 cm accumulation, 25 to 35 km/h southwest wind, treeline temperatures -7 to -2 °C.

Monday

Cloudy, 10 to 22 cm accumulation, 25 to 45 km/h south southwest wind, treeline temperatures -5 to 1 °C.

Tuesday

Cloudy, 10 cm accumulation, 25 km/h southeast wind, treeline temperatures -8 to 1 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Good day to make conservative terrain choices.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • Be especially cautious as you transition into wind affected terrain.

Régions couvertes