Bulletin d’avalanche

Kananaskis

Mar 29 – 30, 2016Alberta Parks
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Archivé · expiré 11 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

Start early and finish early. Intense solar radiation and very warm temperatures will lead to an increase in hazard levels, possibly reaching HIGH. In addition to the problems discussed below, cornices and their underlying slopes should be avoided.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–4
    Slabs averaging 50cm thick are still found in lee and cross-loaded terrain in the Alpine. If triggered, these could step down to a deeper layer. There is also concern on solar aspects for a slab to fail on one of the numerous buried crust interfaces.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–3
    Intense solar radiation and warm temperatures will lead to loose wet avalanches beginning on SE slopes in the morning and moving to S and W aspects through the day.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    3–6
    The current snowpack structure of dense mid-pack overlying as much as 80cm of weak facets is a recipe for full depth avalanches. Triggering from shallow snowpack areas is a particular concern.

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

Wednesday should be cloudy with sunny periods and isolated wet flurries (possibly rain). Freezing levels will climb to 2600m. Alpine temperatures are expected to reach a high of 2 C.  Ridge-top winds will be out of the north at 20 km/h gusting to 50 km/h.

Avalanche Summary

Several loose wet avalanches up to size 2.0 were observed today in steep alpine terrain on solar aspects. Many of these initiated from shallow rocky areas.

Snowpack Summary

The snowpack is settling under the influence of intense solar radiation and daytime heating. Moist snow observed today on all solar aspects up to mountain top and on northerly aspects up to 2200m. Numerous buried crusts are found on all but sheltered north aspects, and many of these crusts are producing shears in snowpack stability tests in the easy to moderate range. We are also observing consistent shears in the hard range deep in the snowpack on the Jan 6th interface down between 100 and 130cm. The basal layers consist of large depth hoar and facets. Slabs up to 50cm thick are still found in lee and cross-loaded features in the Alpine. Much of the region has a snowpack with a dense mid-pack overlying very weak basal layers which indicates the potential for full depth avalanches, triggered either from a large load (such as a cornice) or from a step-down from an avalanche initiated in the upper snowpack. The snowpack is not yet in typical "spring condition", though it is evolving that way.

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