Avalanche forecast

Purcells

Dec 24 – 25, 2012Avalanche Canada
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Archived · expired 14 years ago

Avalanche danger

Wed
Thu
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low

Highlights

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1–4
    Watch for newly formed and buried windslabs in in the lee of terrain features.
  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–4
    New snow and wind has fueled significant cornice growth. Although unlikely, the right chunk of falling cornice has the potential to kick off a wind slab avalanche in steep terrain.

Confidence

Fair - Timing of incoming weather is uncertain on Thursday

Weather Forecast

Tuesday: Isolated flurries expected, winds light from the south and alpine temperatures near -12.Wednesday: Isolated flurries, generally overcast, winds light to moderate from the southwest and alpine temperatures near -11.Thursday: No precipitation is expected, winds light from the west and alpine temperatures near -12.

Avalanche Summary

Recent reports indicate both natural and skier triggered avalanches to size 1.5 in wind loaded features.  Cornices have also been reported to be touchy in the north of the region.

Snowpack Summary

In the last four days the north of the region received 30 - 50 cm while the zone closer to the Purcell Wilderness Conservancy received closer to 80 cm. A wind event from last week formed relatively deep wind slabs in the alpine. New snow combined with wind has formed fresh windslabs on the surface.  Cornices are also a problem at the highest elevations. The mid-pack is reported to be settling well. I haven't heard of any test results involving the late November surface hoar in the last five days. The early November crust, near the base of the snowpack has also been inactive as of late. It's important to note that professionals are still cautious about these lingering persistent slab problems, but the likelihood of triggering is low. Be wary of steep complex terrain with a shallow snowpack, where triggering a persistent weakness is more likely.

Regions covered