Bulletin d’avalanche

Jasper

Feb 21 – 22, 2018Parks Canada
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Archivé · expiré 9 years ago

Danger d’avalanche

Thu
Fri
Alpin
2 · Modéré
Limite forestière
3 · Marqué
Sous la limite
1 · Faible
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Points saillants

A stiff, persistent slab sitting over weak layers will continue to plague the back-country for the foreseeable future. The greatest concern is at, and just above, treeline however these slabs are represented at all elevations and on all aspects.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2.5
    While the winds have abated, they blew hard, and from a variety of directions last week. Windslabs are hard in the alpine and they exist well into treeline areas. These can be expected to be be sensitive to skier triggering.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1.5–3
    A stiff slab 50 to 90cm thick, sits over sun crusts on south and west aspects, Surface Hoar preserved at, and just above treeline and weak faceted crystals lurking in shallow snowpack features. This is a dangerous problem that is difficult to avoid.

Weather Forecast

Cold arctic air dominating the region. Alpine high forecasted to be -22 for Wednesday with broken skies and light north winds. Brrr!

Snowpack Summary

15cm snow over the last week, and available snow from the previous storms, has been redistributed by strong winds from variable directions to build slabs and wind effect in open areas. A persistent slab sitting on three weak layers down 50 to 80cm can be found throughout the forecast region and has produced many large avalanches traveling full path

Avalanche Summary

No new avalanche activity observed or reported in the last week however an extensive cycle resulted when the persistent slab became overloaded with successive storms totalling 50cm each on January 30th and February 8th. Avalanches to size 3.5 were observed from most aspects and at most elevations with the majority of the action seen around 21-2500m

Confidence

Régions couvertes