Bulletin d’avalanche

Banff Yoho Kootenay

Feb 8 – 9, 2015Parks Canada
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Archivé · expiré 12 years ago

Danger d’avalanche

Sun
Mon
Alpin
3 · Marqué
Limite forestière
4 · Fort
Sous la limite
4 · Fort
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Points saillants

Warm temperatures and an isothermal snowpack at low elevations is keeping the danger rating high. Avalanche control planned for tomorrow on Mt. Bosworth, Field and Stephen. No activities in these areas.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    1–3
    Storm slabs are the primary issue in the upper snowpack and failures will be occurring both within the colder low density and on the January 30th crust interface. This problem will be most prominent in the alpine and treeline bands on all aspects.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    2–4
    The base of the snowpack remains weak due to basal depth hoar/facets. Additional snow load, or a storm slab failure may trigger large to very large avalanches in thin snowpack areas. There were additional avalanches triggered on these facets today.

Confidence

Freezing levels are uncertain on Sunday

Weather Forecast

The intense precipitation is starting to taper off. Expect no more than 10cm of snow over the forecast region over the next couple of days with light west wind.

Snowpack Summary

45 - 70 cm of recent storm overlies a crust from January 30th. The recent heavy precipitation, wind and warmer temperatures have created storm slabs which will put an enormous amount of stress on the January 30th crust interface. The basal facets from Nov 6th could reemerge in step down events with this huge stress to the snowpack.

Avalanche Summary

Avalanche control on Mt. Whymper today produced avalanches up to size 2.5. Fracture line thickness varied between 20 and 60cm with average running distance about 250m. Also, evidence of a widespread cycle up to size 3 throughout the forecast region. Some avalanches running close to full path.

Régions couvertes