Bulletin d’avalanche

South Rockies

Apr 4 – 5, 2012Avalanche Canada
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Archivé · expiré 14 years ago

Danger d’avalanche

Fri
Sat
Alpin
4 · Fort
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    2–5
    Forecast new snow and strong southwest winds are expected to develop new windslabs in the alpine and at treeline. Windslab avalanches may trigger storm slabs or deeply buried facets, resulting in very large avalanches.

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    3–7
    Large cornices are expected to develop new growth during the forecast storm. Cornice falls may trigger storm slabs or deeply buried facets.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2–6
    Forecast new snow is expected to add a new load to the 60-100 cm storm slab that exists. Storm slabs may fail naturally during the storm or be easily triggered. Storm slabs may be moist or wet below treeline.

Confidence

Fair - Forecast snowfall amounts are uncertain on Thursday

Weather Forecast

The storm on Wednesday was a little bit slower and a little further west than originally forecast. Heavy precipitation is forecast for Wednesday evening and overnight into Thursday morning, bringing about 20 mm of precipitation. The wind is forecast to be about 70km/Hr out of the south-southeast tonight at ridgetops. As the freezing level drops tonight, the precipitation could become up to about 30 cm of snow at higher elevations. The storm is expected to move east into Alberta by Thursday noon. A ridge of high pressure is expected to move into the region by Friday bringing clear skies and light winds with freezing levels rising to about 1400 metres during the day.

Avalanche Summary

No new avalanches reported. Expect avalanche activity to increase with forecast new snow and wind.

Snowpack Summary

There was a good re-freeze reported from Monday night and again on Tuesday night, that has resulted in a supportive melt-freeze crust on all aspects up to about 2200 metres. North aspetcs may be dry down to about 2000 metres in some areas. Southerly aspects became moist in the alpine on Tuesday, but snowballing and wet point releases were limited to size 1.0. Forecast new snow and strong winds are expected to create new windslabs and add a new load to storm slabs. Deep weak layers may continue to be triggered by large loads like cornice falls or storm slab avalanches.

Régions couvertes