Bulletin d’avalanche

Kananaskis

Feb 24 – 25, 2017Alberta Parks
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Archivé · expiré 10 years ago

Danger d’avalanche

Sat
Sun
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Points saillants

Natural avalanche activity has largely subsided, but the potential for human-triggering remains. Due to the weak basal structure of the snowpack, very large avalanches are possible. Conservative route selection is advised.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2
    These slabs are now lightly buried under the new snow from the last few days. So far these have been an issue in steep convex terrain and below cliffs. Cross-loaded areas at treeline also have the slabs, however these are a bit more stubborn.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–3
    Triggering this layer is still a possibility in thin areas. Expect large propagations.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–4
    We are approaching the "low probability, high consequence" phase of the winter. Respect the potential for this layer to react to large triggers, or weak shallow areas.

Confidence

High -

Weather Forecast

The next few days will be cool (highs near -15 °C)  with light flurries. Snow accumulations are not expected to be significant. Winds will be moderate from the West on Saturday and then switch to light from the East on Sunday.

Avalanche Summary

Nothing new today, but some large naturally triggered avalanches have occurred over the past week.

Snowpack Summary

Recent storm snow has settled to an average of 20cm deep, with very little wind effect in most areas below 2500m. On steep solar aspects there is a buried suncrust (Feb 17th layer) down 20-30cm. Beneath this, the upper snowpack remains well settled with denser slabs as the 50cm depth is reached. The basal layers are alive and well and vary between 30-50cm thick, and is a dog's breakfast of crusts, facets and depth hoar. Snowpack stability tests today indicate a sudden collapse failure within the basal layers in the moderate range. These tests were done in a slightly shallower morainal feature, and indicate the possibility of full-depth avalanches if the "sweet spot " is triggered.

Régions couvertes