Bulletin d’avalanche

Waterton Lakes

Jan 28 – 31, 2016Parks Canada
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Archivé · expiré 11 years ago

Danger d’avalanche

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

The potential for buried persistent weak layers to have created a low probability/high consequence avalanche problem makes for decreased confidence.  Evaluate the snowpack and terrain carefully before exposing yourself to larger features.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1–2
    While stubborn to trigger, windslabs have the potential step down to previously buried weak layers.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    1–3
    A weak layers buried in early January and early December have not been ruled out as the potential failure plane of several large, recent slab avalanches. While the probability of triggering these layers is low, the consequences will be significant.

  • Loose Wet

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

Weather Forecast

Ongoing chinook winds (strong to extreme from the west) and warm temperatures (highs of 10 deg for the townsite and freezing levels as high as 2100m) will begin to abate Thursday afternoon, as the trailing end of a cold front brings increasing cloudiness, cooling temperatures and light precipitation to the area through Friday.

Snowpack Summary

Strong to extreme chinook (westerly) winds continue to build windslabs in lees and windpressed surfaces in exposed areas. These windslabs are stubborn to trigger but may propagate widely if they initiate on/step down to previously buried weak layers; a Jan 4th crust/surface hoar (solar/shady aspects) down 40-70cm, and a Dec 9th crust down 70-120cm.

Avalanche Summary

A few isolated large avalanches were observed locally last weekend, these are suspected to have been persistent slabs failing on the Jan 4 crust/surface hoar layer. Neighboring ski operations have been reporting isolated large persistent slab avalanches failing on the Dec. 9th crust.

Confidence

Freezing levels are uncertain

Régions couvertes