Bulletin d’avalanche

Banff Yoho Kootenay

Dec 6 – 7, 2014Parks Canada
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Archivé · expiré 12 years ago

Danger d’avalanche

Sat
Sun
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Watch the temperatures on Saturday as freezing levels are expected to rise accompanied by light winds and light snow. Human triggered avalanches likelihood will rise as the snowpack has poor structure and is in a fragile state awaiting a trigger. PJ

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2
    Although cold temperatures have reduced the tension in many wind slabs there are places that have been ravaged by winds from many directions, especially in the alpine. Watch for pockets of hard slab near ridge tops and cross loaded features.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2–3
    The primary problem in the snowpack is the interface between the recent storm snow and the November 6th and 24th facet/crust interfaces. This is the problem responsible for the majority of the avalanches in the past week. Watch for remote triggering.

Weather Forecast

Westerly flow will bring light snowfall amounts and light winds for the next few days but the main criteria this weekend will be warming temperature & rising freezing levels exceeding 1800 meters by Saturday afternoon. This will be one of the most significant weather criteria and needs to be monitored closely.

Snowpack Summary

The storm snow from last week's storm is a soft slab in sheltered locations and wind scoured and hard wind slab in open terrain at tree line and above. The lower half of the snowpack is complex and poorly structured, comprised of the facets (Nov 24th) at the interface of the recent storm snow and a series of thin crusts (Nov 6th) and depth hoar.

Avalanche Summary

There has not been a great deal of natural activity observed however explosive results were reported from around the ski areas and produced slab avalanches up to size 2.5 with the slab failing on the basal facets and crusts right on the ground. These kinds avalanches are a dirty & rough ride through scree, rocks and trees & are human trigger able.

Confidence

Freezing levels are uncertain on Saturday

Régions couvertes