Bulletin d’avalanche

Northwest Coastal

Dec 10 – 11, 2012Avalanche Canada
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Archivé · expiré 14 years ago

Danger d’avalanche

Wed
Thu
Alpin
4 · Fort
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    1–5
    Widespread wind slabs are likely to be found on alpine slopes and behind ridges and ribs at treeline and below.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    2–7
    A deeply buried facet/crust weakness exists. While the likelihood of triggering it is low, the consequences could be a very large and destructive avalanche.

Confidence

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

Weather Forecast

Monday night: Expect winds of up to 100 km/h from the SW and about 20 cm of snow overnight. Alpine temp -5.Tuesday: Westerly winds dropping to moderate. Alpine temp -6. Light snow. Freezing level 800 m, dropping to surface overnight.Wed: Light westerly winds. Alpine temp -7. Freezing level 100 m. Light snow.Thurs: Moderate SW winds. Alpine temp -3. Freezing level 800 m. 5 cm snow.

Avalanche Summary

On Sunday, natural activity to size 2.5 occurred in response to very strong winds, new snow and warming. This cycle is expected to continue through Monday and Tuesday. 

Snowpack Summary

Storm snow is being redistributed by very strong winds, creating wind slabs on a variety of slopes. In sheltered areas below treeline, loose sluff may be encountered. New wind slabs may be sitting above widespread surface hoar, making a touchy combination. The surface hoar was particularly noticeable in the Shames backcountry on Saturday. In general the mid-pack is gaining strength. A November facet/crust layer can be found near the base of the snowpack. Observations of this layer are limited, however recent explosives testing suggests it may be more problematic in the north of the region than in the south. Above about 1000 m, the snowpack  is 150-200 cm deep. Below 1000 m, the snowpack is only just reaching threshold.

Régions couvertes