Bulletin d’avalanche

Jasper

Dec 21 – 22, 2016Parks Canada
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Archivé · expiré 10 years ago

Danger d’avalanche

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

Three days of strong SW winds have changed the landscape. Cautious route finding and conservative decisions are called for.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2
    72 hours of intense ridgetop transport due to strong SW winds has created windslabs. Numerous natural avalanches were observed from a variety of aspects, particularly alpine gulley features and planar NE slopes.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1–3
    The depth of this crust is now highly variable, and may as deep as 1m in lee areas that have received significant loading due to strong SW winds. Careful evaluation of this interface is essential with this new loading pattern.

  • Loose Dry

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2
    Although there has been extensive scouring, the weak facets will likely continue to shed from steep rocky terrain.

Confidence

Wind effect is extremely variable

Weather Forecast

Moderate to Strong SW winds will continue through Wednesday night and maybe 5-10cm of snow by Thursday morning. The Icefields area may get 10-20cm by Friday. Temperatures will hover around -10 to -15. 

Snowpack Summary

Strong SW winds and ridge top transport of faceted snow has occurred for the past 72 hours. Expect new wind slabs in lee areas and cross loaded gullies. Suspect surface hoar (Dec 11) in sheltered NE aspects around treeline (2100-2300m). Nov crust is now on the surface in scoured areas and as deep as 1m+ on lee aspects.

Avalanche Summary

Tuesday's patrol noted a size 1.5 slab 100m below the crevasse rescue wind lip on parkers ridge. It was 80m wide and 40cm deep. Monday was noted numerous wind slabs to sz 1.5 in alpine gulley features and steep NE aspects. We expect that  these types of terrain features will be re-loaded with the current strong winds.

Régions couvertes