Bulletin d’avalanche

South Rockies

Jan 12 – 13, 2014Avalanche Canada
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Archivé · expiré 13 years ago

Danger d’avalanche

Tue
Wed
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    3–6
      Recent avalanches stepped down to the deeper persistent layers showing that they are still active and proving that they could still be triggered by a sledder or rider.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–4
    Developing windslabs lee of strong W winds and buried windslabs is be the main concern for tomorrow. Beware of the possibility of loose avalanches in steep terrain and of storm instabilities that could linger.

Confidence

Fair - Intensity of incoming weather systems is uncertain

Weather Forecast

Tonight and Monday: Light to moderate precipitation amounts are expected tonight with extreme W winds. Freezing levels are expected to rise to 1200 m on Monday. Tuesday: An upper ridge is building over the region which will give the storm pattern a break. Trace accumulations, a mix of sun and cloud, strong W winds and freezing levels rising to 2000 m. Wednesday: The ridge brings dry, clear and warm temperatures over the Southern part of the province with strong winds from the NW.

Avalanche Summary

Multiple avalanches were reported yesterday up to size 3 on slopes lee of wind, some of which are suspected to have stepped down to deeper instabilities.

Snowpack Summary

Accumulations forecasted tonight and strong W winds is keeping avalanche conditions dangerous for tomorrow. The new windslabs lee of W winds below ridgetop will most likely be very touchy and could possibly slide naturally. Watch for loose snow avalanches in steeper terrain as well. Cornices will continue building and could fall possibly triggering big avalanches that could step down to deeper layers. The late November facet/crust and surface hoar layer down between 70-100 cm and the depth hoar and basal facets situated at the bottom of the snowpack are suspected to have reacted to the recent storm load and avalanches may have stepped down to these layers. These persistent weak layers are showing a high spatial variability and also some variable snowpack and sledding test results. In other words, they are spotty and hard to predict. The facet/crust layer at treeline has been mostly reactive on E aspects and the depth hoar layer in the alpine is still concern especially where the snowpack is thinner.

Régions couvertes