Bulletin d’avalanche

Jasper

Jan 6 – 7, 2023Avalanche Canada
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Archivé · expiré 4 years ago

Danger d’avalanche

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

Increasing winds will promote wind slab development at tree line and above. These fresh wind slabs sit over a generally weak, faceted snowpack.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–2

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2.5

    A varied slab sits over the December 17th facet layer, 25-50cm down. This problem is significant at all elevations but most reactive in open tree line features and in the alpine where you can expect a stiffer, likely more reactive slab. If triggered, it is possible to step down to the deep persistent facets combo near the ground.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1.5–3

    The bottom of the snow pack is inherently weak with well developed Facets and Depth Hoar. Avalanches initiating in the upper snowpack are likely to step down to this layer and gain significant mass.

Confidence

Moderate

Avalanche Summary

A size 2.5 natural avalanche was observed off the north face of Mt. Kitchener on Thursday, Jan 5. Unable to identify the type of avalanche or failure plane due to visibility.

Snowpack Summary

Widespread surface hoar growth throughout the Jasper region. The top 20-40cm has a varying density with pockets of wind slab developing in exposed terrain at treeline and above. The upper snowpack sits over the Dec 17 persistent weak layer buried 30-40cm deep. The lower snowpack is heavily faceted with depth hoar present at the base of the snowpack. The snowpack ranges from 50-120cm.

Weather Summary

Friday

Mainly cloudy with isolated flurries.

Precipitation: Trace.

Alpine temperature: High -6 °C.

Ridge wind southwest: 15 km/h gusting to 45 km/h.

Freezing level: 1400 metres.

Saturday

Mainly cloudy.

Precipitation: Nil.

Alpine temperature: Low -11 °C, High -6 °C.

Ridge wind southwest: 15-30 km/h.

Freezing level at valley bottom.

Sunday

Mainly cloudy with isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -11 °C, High -7 °C.

Ridge wind southwest: 10 km/h.

Freezing level at valley bottom.

Terrain and Travel Advice

  • The trees are not a safe haven, travel at treeline requires expert knowledge and diligence.
  • Make conservative terrain choices and avoid overhead hazard.

Régions couvertes