Bulletin d’avalanche

Kootenay Boundary

Mar 9 – 10, 2016Avalanche Canada
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Archivé · expiré 11 years ago

Danger d’avalanche

Fri
Sat
Alpin
4 · Fort
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Heavy loading from snow, wind and rain will cause avalanche danger to spike.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    2–5
    Deeply buried surface hoar will likely produce large natural avalanches with heavy loading from snow, wind and rain, as well as shallower slab avalanches stepping down.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    1–4
    Heavy loading from snow, wind and rain is expected to result in widespread natural storm and wind slab avalanches.

Confidence

High

Weather Forecast

THURSDAY: Moderate snowfall starting overnight Wednesday and continuing throughout the day with over 30-40cm of accumulation expected. Freezing levels briefly reaching 2000m midday, and extreme southwesterly ridgetop winds. FRIDAY: A mix of sun and cloud with lingering flurries/showers and freezing levels back up to 2000m. Winds should ease off. SATURDAY Mainly cloudy with continued light precipitation picking up in the afternoon. Freezing levels hovering around 2000m and strong southwesterly ridgetop winds.

Avalanche Summary

Reports from Tuesday include several skier and explosive triggered 20-30cm thick Size 1-2 wind and storm slab avalanches as well as loose dry sluffs in steep terrain. Of note were two 50-80cm deep Size 2-2.5 persistent slab avalanches running on the late February surface hoar remotely triggered by a snowcat 10m away. Natural storm and wind slab avalanche activity is expected to increase with forecast heavy loading from snow, wind and rain.

Snowpack Summary

Up to 35cm of recent snow is bonding poorly to a widespread rain crust which extends into alpine elevations. A persistent weak layer buried late-February is now typically down 40-70cm and may still be sensitive to human triggers as indicated by recent avalanche activity and hard but sudden snowpack test results. This weakness is widespread buried surface hoar above 1700m, and a crust potentially with associated facets on previously sun-exposed slopes (primarily south aspects). 80-100cm below the surface you will likely find the mid-February crust/facet/surface hoar layer, which has been inactive lately.

Régions couvertes