Bulletin d’avalanche

Purcells

Dec 14 – 15, 2011Avalanche Canada
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Archivé · expiré 15 years ago

Danger d’avalanche

Fri
Sat
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1–3
    Old windslabs lurk in lee locations in the alpine. The trace of new snow may hide the older slabs and develop into new softslabs with the forecasted flurries and wind. For more info on incremental loading, check the forecaster blog.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–5
    The weak facetted layer near the ground may still be triggered in shallow snowpack areas with the common trigger points being convexities, rocks or clumps of small trees.

Confidence

Fair - Intensity of incoming weather is uncertain

Weather Forecast

Thursday: Expect the clouds to dissipate through the day, with a chance of flurries tapering into the evening. Winds should be light westerlies with temperatures reaching -6. Friday & Saturday: Clouds rebuild bringing intermittent flurries giving as much as 10cm each day. Winds in front of this disturbance will turn westerly. Expect daytime highs of -4.

Avalanche Summary

No new avalanches.

Snowpack Summary

5-10cm of new snow has fallen since the 10th of December. This overlies surface hoar, surface facets, old windslabs and sun crusts (on steep south through west aspects). Winds have been sporadic in this period, creating isolated new soft slabs in immediate lee locations. Moving forward, the avalanche danger will increase as the load increases (either by new snow or wind). Be locally aware of changes and if obvious signs of instability are present (cracking, whumphing, recent activity on adjacent slopes) or rapid loading is taking place (heavy snowfall or strong winds) then scale down your terrain choices accordingly. Snow depths are quite variable through the region with 130-150cm in the alpine. There is still concern for triggering the weak basal facets/depth hoar, as these layers have shown sudden collapse results in stability test in shallow areas.

Régions couvertes