Bulletin d’avalanche

Kootenay Boundary

Dec 14 – 15, 2012Avalanche Canada
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Archivé · expiré 14 years ago

Danger d’avalanche

Sun
Mon
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 - Intensity of incoming weather is uncertain

Weather Forecast

Synopsis: A series of weakened frontal systems will affect southern interior over the next few days. The strongest system is forecast to affect the region on Monday.Saturday: Light snow – 5-10 cm. Winds should be moderate from the SW. The freezing level should remain near valley bottom. Sunday: Lingering flurries with snow possibly developing overnight. Winds remain moderate from the W-SW. Freezing level near valley bottom. Monday: Moderate to locally heavy snow. Freezing level could jump to 800 m.

Avalanche Summary

A couple small avalanches were observed in the Kootenay Pass area on Wednesday. One was a size 1 slab that was triggered on lower elevation (~1400 m) cut block. The slide was approximately 45 cm deep and may have released on a rain crust. The other event was a natural avalanche on a wind loaded slope immediately below ridge top.

Snowpack Summary

Recent winds have been redistributing the low density surface snow onto leeward slopes creating 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