Bulletin d’avalanche

Jasper

Dec 8 – 9, 2021
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Archivé · expiré 5 years ago

Danger d’avalanche

Thu
Fri
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible

Points saillants

Natural avalanche activity has tapered off yet triggering of full depth avalanches on the basal weakness remains possible in specific tree line and alpine features. Excellent quality riding can be found in sheltered terrain!

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1.5–2.5

    A triggered windslab has a potential to step down to deeper instabilities with a more destructive potential. Consider testing smaller slopes before committing to terrain with potential for larger propagation. Watch for hollow sounds and cracking.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3.5

    Natural activity is decreasing as the recent new snow stabilizes, however, triggering this layer would be a high consequence event so cautious decisions and thorough investigation is necessary.

Weather Forecast

Wednesday: Scattered flurries. Accumulation: 8 cm. Alpine temperature: Low -12 C, High -8 C. Ridge wind west: 20 km/h

Thursday: Isolated flurries. Precipitation: Trace. Alpine temperature: Low -16 C, High -13 C. Ridge wind west: 20 km/h

Friday:  Cloudy scattered flurries: Accumulation: 4cm. Alpine temperature: Low -18 C, High -12 C

Snowpack Summary

Surface facetting and spotty surface hoar growth noted.  Storm snow from last week has been stripped from exposed windward alpine features.  In sheltered areas 20-30cm of settled storm snow sits atop of a supportive midpack.  Our basal crust/facet/depth hoar combo near the ground remains a layer of concern. Snowpack depth 100-140cm Icefields area.

Avalanche Summary

No new avalanches observed in the Icefields area on Monday. Maligne area field team reported no new avalanches on Sunday. Although natural avalanche activity has tapered off, human triggering of large avalanches remains possible especially in features with variable thin to thick snow depths in the alpine and at treeline.

Confidence

Due to the number and quality of field observations

Régions couvertes