Bulletin d’avalanche

Northwest Coastal

Nov 27 – 28, 2011Avalanche Canada
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Archivé · expiré 15 years ago

Danger d’avalanche

Tue
Wed
Alpin
4 · Fort
Limite forestière
4 · Fort
Sous la limite
4 · Fort
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Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    2–6
    Expect to find deep and dense wind slabs in exposed terrain well below ridge crests.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    2–5
    Weaknesses may exist within or under the recent storm snow.

Confidence

Fair - Due to limited field observations

Weather Forecast

Another strong frontal system should reach the area by Monday morning bringing heavy snowfall and strong southwesterly winds. Expect another 25-40cm with this storm. The freezing level should be around 1000-1200m on Monday. Precipitation should taper off on Tuesday as a ridge of high pressure builds in. Mainly sunny skies are expected on Wednesday. The freezing level should be around 500-800m on Tuesday and Wednesday.

Avalanche Summary

Recent reports are limited to the run out zones along the highway corridors near Bear Pass and Terrace. I expect a widespread natural avalanche cycle occurred in many areas on Saturday and into Sunday.

Snowpack Summary

Saturdays system dumped another 50-75cm in many areas. The snowpack depth near treeline is already around 300cm. Fluctuating freezing levels and varying precipitation intensity and wind throughout the recent storms has probably resulted in various weaknesses within upper snowpack. A buried surface hoar layer may be found down close to 100cm, but there is no recent information on the presence and sensitivity of this layer. The mid and lower snowpack is generally well settled and strong with an old rain crust near the ground.

Régions couvertes