Bulletin d’avalanche

Purcells

Jan 28 – 29, 2014Avalanche Canada
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Archivé · expiré 13 years ago

Danger d’avalanche

Thu
Fri
Alpin
1 · Faible
Limite forestière
1 · Faible
Sous la limite
1 · Faible

Points saillants

Touchy thin new wind slabs may develop exposed lee terrain on Wednesday if we see more snowfall and/or wind than forecast. If so, watch your exposure to terrain traps below.

Problèmes avalancheux

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    3–6
    A crust/facet weakness near the base of the snowpack continues to linger but is typically unreactive to triggering. This remains a low probability, high consequence problem for some areas of the region.

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Wednesday: Mainly cloudy with periods of light snow around 5 cm in the north and 10 cm in the south. The freezing level is at valley bottom. Winds are light to moderate from the W-NW. Thursday: Mainly cloudy with a chance of flurries. Temperatures should cool a few degrees to around -10 at treeline. Winds are light from the north. Friday: Mainly sunny. Treeline temperatures are around -12 during the day and -20 overnight.

Avalanche Summary

With the cooler temperatures and increased cloud cover on Sunday, natural avalanche activity appears to have mostly stopped. No new avalanches have been reported.

Snowpack Summary

The recent dry, warm weather has generally consolidated the upper snowpack. As temperatures now begin to cool, stability in the upper snowpack should increase further. Keep in mind that 'Low Hazard' does not mean 'No Hazard' and that residual risk of avalanches still exists. Old, stubborn wind slabs may still exist in isolated areas. A basal facet/crust combo (weak sugary snow above and below a crust) near the ground is still a concern in some areas. The depth of this layer makes triggering an avalanche on it unlikely (maybe a heavy load on a thin spot in steep terrain, rapid temperature change, or cornice fall), but the consequences would be large and very destructive.Widespread large surface hoar was reported throughout the region. This layer is now probably buried by a few centimetres of snow. In some places the surface hoar may have been sitting on a crust, it may have only been a sun crust, and it may even have included sugary faceted snow. At any rate, it looks like this layer will be one to keep a close eye on in the coming weeks.

Régions couvertes