Bulletin d’avalanche

Northwest Inland

Dec 2 – 3, 2012Avalanche Canada
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Archivé · expiré 14 years ago

Danger d’avalanche

Tue
Wed
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Limited field observations and reports exist from this region. Conditions may be variable. It is important to be familiar with the snowpack and avalanche problems that may exist in your local mountains.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–4
    Wind slabs have formed; especially on lee slopes, gully features, and behind ridges. Natural avalanche activity is possible with continued loading. Rider triggering is likely, especially on steep convex slopes.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–6
    Basal facet/crust weaknesses are often prone to remote triggering and step down avalanches. Typical trigger points include thin rocky areas. They may be difficult to trigger, but deep persistent slab avalanches are often very large.

Confidence

Poor - Due to limited field observations for the entire period

Weather Forecast

A broad upper trough remains just offshore while a cooler, unstable onshore westerly flow will persist and strengthen through Monday. A multitude of systems will bring light –moderate precipitation, and strong SW winds, while the arctic air should be pushed out of the region by Monday. Monday into Tuesday will see the heaviest amount of precipitation during the forecast period. Monday: Fzlvl’s surface, snow amounts near 5 cm, ridgetop winds SE 20- gusting 60 km/hr, and alpine temps -8.Tuesday: Fzlvl’s surface, snow amounts 10-20 cm, ridgetop winds SW 30-gusting to 70 km/hr, alpine temps -7.Wednesday: Fzlvl’s surface, snow amounts near 5-10 cm, ridgetop winds S 30 km/hr, and alpine temps -10.

Avalanche Summary

No new natural avalanches have been reported. Currently, information is extremely sparse for this region. If you have been out exploring the backcountry and enjoying the snow, please share your snowpack and /or avalanche observations with us.Email info to forecaster.ca.

Snowpack Summary

Wind slab instabilities exist in the upper snowpack at treeline and in the alpine. They may be touchy to rider triggers; especially on leeward slopes and behind terrain features where pockets of wind slab easily build. At treeline depths in the southern part of the region range between 70-125 cm, but highly variable in the alpine with deep wind drifts and scoured slopes in exposed areas. Generally, the mid-pack is gaining strength and possibly even bridging the persistent weakness below.Digging down deeper is the early November facet/crust persistent layer. This crust sits near the base of the snowpack down 80-130 cm. Test results on this layer earlier this week produced moderate (drops) I have no current observations to suggest the snow above or below this interface is gaining strength, or weakening. In most areas, because this weakness is located near the ground, any associated avalanche activity will likely be limited to slopes with smooth ground cover.

Régions couvertes