Bulletin d’avalanche

Kootenay Boundary

Dec 14 – 15, 2011Avalanche Canada
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Archivé · expiré 15 years ago

Danger d’avalanche

Fri
Sat
Alpin
2 · Modéré
Limite forestière
1 · Faible
Sous la limite
1 · Faible

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2
    Fresh soft wind slabs are expected to develop below ridgecrests and behind terrain features throughout the forecast period.

Confidence

Fair - Intensity of incoming weather is uncertain on Friday

Weather Forecast

Thursday: Snow and wind tapering off throughout the day with 5-10cm total storm snow expected by the evening. Moderate southwesterly winds are expected to shift to northwesterlies with a gradual clearing throughout the day. A series of systems are forecast to affect the region for Friday through Saturday with generally light precipitation and light to moderate westerly winds. Freezing levels are expected to remain near valley bottoms for the forecast period.

Avalanche Summary

There have been no recent reports of avalanches. Fresh soft wind slabs are expected to form and become an avalanche problem.

Snowpack Summary

Large surface hoar and faceted powder on sheltered shady slopes, and a surface crust on sun-exposed slopes, is now lightly buried in most locations and should continue to get incrementally buried over the forecast period. Assuming the structure of this current snow surface is preserved long enough for a sufficiently thick and cohesive slab to bury it, then a highly unstable situation should develop. Particularly where surface hoar and/or faceted crystals are associated with a weak crust. Generally speaking the longer surface snow is exposed to the elements before it gets burred, the more likely it is to become a serious problem. The mid and lower snowpack are generally well settled and strong, but faceted. Recent easy test results on basal facets and depth hoar necessitates caution on wind-exposed slopes with highly variable snowpack depths, where this deep persistent weakness could be triggered from a shallow spot. Check out the Forecaster's Blog link below for more general snowpack discussion and good advice.

Régions couvertes