Bulletin d’avalanche

Jasper

Apr 8 – 9, 2014Parks Canada
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Archivé · expiré 12 years ago

Danger d’avalanche

Thu
Fri
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Points saillants

Mild temperatures, rain and strong winds are decreasing the snowpack stability. Several large avalanches from treeline and below occurred on Tuesday near the Columbia Icefields.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    Strong SW winds on Tuesday have created slab conditions. SE aspects where buried sun crusts may provide a sliding surface should be approached with caution. Thin slabs will likely step down to the basal weaknesses near ground producing large slides.

  • Wet Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2–3
    With cooling temperatures this condition will stabilize. Rain and solar exposure will increase the danger. Weather conditions will be variable across the region. Snowballing and pin wheels should be regarded as signs of deteriorating conditions.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2–3
    Continued wind loading and warming temperatures have increased the triggering sensitivity of this weakness. Strong SW winds on Tuesday were present across the region but most noticeable in the Columbia Icefields area

Weather Forecast

Cooling temperatures over the next 48 hours with the chance of snow flurries. The SW flow will become more westerly with the freezing levels dropping to the valley bottom overnight and not reaching the treeline during the day. Cooler temperatures are forecast for the Icefields area where the greater amounts of snow can also be expected at elevation

Snowpack Summary

At treeline and below warming temperatures and rain has increasing the temperature of the snowpack. Moist snow in the upper pack can be anticipated. Surface crusts will form when temps drop. Solar facing slopes close to treeline may have buried crusts with slab snow above. Deeply buried weaknesses near ground. Windslabs in the alpine.

Avalanche Summary

Slab and point release avalanches observed Tuesday up to size 2.5 from treeline and below. All events are stepping to ground. Most are being triggered by warm temperatures and rain. One or two of these events started above treeline in areas where strong and extreme winds, from the SW, are developing wind slabs. These to are steeping down to ground.

Confidence

Freezing levels are uncertain on Wednesday

Régions couvertes