Bulletin d’avalanche

Jasper

Apr 1, 2017Parks Canada
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Archivé · expiré 10 years ago

Danger d’avalanche

Sun
Mon
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Points saillants

Solar radiation will rapidly and dramatically increase the avalanche danger at all elevations if it occurs . Pay close attention to freezing levels.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    Strong  SW winds in the alpine have produced wind slabs from recent snow fall. These will be most reactive at upper elevations near ridge features. If triggered they may step down to deep basal weakness.

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–3
    Large cornices on ridge top lee features continue to build with strong SW winds. Their sheer mass is a problem. Recent alpine releases have resulted in large slab avalanches.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    2–4
    The deep persistent slab can be triggered by travelers from shallow or weak locations or naturally from large loads such as cornice failure or windslab avalanches.

Weather Forecast

Snow at the icefields over Sat and Sun, total 15cm. Winds Mod SW alpine highs -4. FzL 1,800m

Snowpack Summary

Temp surface crusts below 1,700m on all aspects, extending to treeline on Solar facing slopes. Below the crust at lower elevations the snowpack is turning isothermal.  Thin soft wind slabs at ridge features which stiffen and thicken with elevation. The midpack is consolidated and providing bridging strength over a weak and faceted snowpack base.

Avalanche Summary

Several slab avalanches  size 2-3  from steep easterly facing alpine terrain. These were likely triggered by cornice failures and stepped down to basal layers running into the valley bottom. Explosive work at lower elevations produced several class 2 moist snow avalanches.

Confidence

Freezing levels are uncertain on Sunday

Régions couvertes