Bulletin d’avalanche

Jasper

Apr 1 – 2, 2017Parks Canada
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Archivé · expiré 10 years ago

Danger d’avalanche

Mon
Tue
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Points saillants

Resist the temptation to travel on big slopes that have not yet avalanched.  Weaknesses deep in the snowpack can be triggered from shallow snowpack areas and have the potential to run full path. 

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–3
    New windslab formed by recent SW winds could be reactive and if triggered, could step down to the deep persistent slab.

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–3
    Cornice failure is hard to predict but is more likely with inputs like solar radiation and wind-loading.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–3
    This problem is unlikely to disappear.  It can be triggered by large loads like cornice fall or windslab failure.  Human triggering is most likely from shallow spots or on steep unsupported slopes.

Confidence

Timing or intensity of solar radiation is uncertain on Tuesday

Weather Forecast

10 cm of snow expected Saturday night with easing SW winds.  Freezing level falling to 1300 m.  Cloudy spring-like weather Sunday and Monday.  Sun and warm temperatures are predicting starting on Tuesday.

Snowpack Summary

Recent large cornices failures have triggered the deep persistent slab creating size 3 avalanches. Previous S-M SW winds formed windslab on lee aspects. A thick and strengthening mid-pack is bridging basal weakness. The lower snowpack is weak with depth hoar, Nov rain crust and basal facets. Isothermal conditions below tree-line on solar aspects.

Avalanche Summary

Recent cornice and windslab failures have triggered the deep persistent slab creating large full path avalanches that are traveling well into historic run-outs. Loose wet avalanches have been occurring on steeper south and west aspect below tree-line.

Régions couvertes