Bulletin d’avalanche

Kootenay Boundary

Dec 13 – 14, 2012Avalanche Canada
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Archivé · expiré 14 years ago

Danger d’avalanche

Sat
Sun
Alpin
2 · Modéré
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
    1–4
    A soft slab on the surface is stiffening with with continued settlement and wind-exposure, and may be triggered by light additional loads like a skier or rider.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–5
    Slopes that roll over such that the slab is unsupported from below. Particularly in areas with a shallower snowpack.

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period

Weather Forecast

Synopsis: A series of weather systems and weak ridges are forecast to cross the province over the next few days. We should see light to moderate snowfall each day. Friday: Flurries ending in the morning, then a mix of sun and cloud. Freezing level around 800 m. Winds are light to moderate from the W-NW. Saturday: 10-15 cm of snow. Freezing level steady around 800 m. Winds increase to strong from the W-SW. Sunday: Moderate snow (15-20 cm). Winds remain moderate to strong. Freezing level rising to 1000 m.

Avalanche Summary

One size 1 natural slab avalanche was observed in a lee feature immediately below the ridge top in the Kootenay Pass area on Wednesday. Expect fresh wind slabs and loose surface snow to be sensitive to human triggers.

Snowpack Summary

Recent winds have been redistributing the low density surface snow onto leeward slopes creating thin wind slabs that have been giving moderate compression tests results. Surface hoar buried at the end of November recently gave moderate to hard but sudden results in compression tests where it has been found as large as 10mm down 90-120cm, or shallower in the Rossland Range where it more of a concern. On a southwest aspect at 2020m in a shallow faceted snowpack area of Kootenay Pass, facets sitting on a rain crust recently gave moderate but resistant compression test results down 30-35cm. Recent reports suggest that the early November facet/crust deep persistent basal weakness has been producing inconsistent, but occasionally sudden snowpack test results and remains a concern. Keep this on your radar, especially when traveling in areas at higher elevations that have a smooth ground cover where the existing crust is uniform and consistent.

Régions couvertes