Avalanche forecast

Northwest Inland

Dec 30 – 31, 2012Avalanche Canada
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Avalanche danger

Tue
Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–4
    Watch for new wind slabs behind ridges and terrain breaks that could be formed with the moderate and strong South winds expected. These could be triggered by the weight of a person or snowmobile.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–5
    A deeply buried facet/crust weakness exists near the base of the snowpack. This layer could be triggered by large loads such as a cornice collapse or from a thin-spot trigger point.

Confidence

Fair - Due to limited field observations

Weather Forecast

Sunday night and Monday: The weakening front should reach the North coast during the night bringing light precipitation over the western part of the region and traces of precipitation during the day and moderate Southeasterly winds. Freezing levels should stay at valley bottom. Tuesday: The ridge of high pressure rebuilds to give place to clearer skies but similar light winds from the Southeast. Temperatures are expected to warm up slightly reaching -4 C in the alpine. Cloud cover should increase later during the day goes as another frontal system approaches. Wednesday: The optimistic models show considerable amounts of precipitation with the coming system and southerly winds.

Avalanche Summary

Minor surface sluffing.(dry loose avalanche) has been reported in the Howson's area. 

Snowpack Summary

As a general overview, a shallow snowpack (about 1m deep) exists, with facets that have continued to develop with this week's cool arctic air. Older wind event have scoured some alpine slopes to ground and the forecasted strong Southerly winds for tonight and tomorrow could also redistribute the snow in the alpine and at treeline to create new windslabs.  The distribution of these windslabs will be quite variable and some areas were reported to have no wind-effect at all. Indeed, cold density snow is still possible to find at the surface in wind sheltered areas. Below treeline, very loose cold snow is sluffing easily from steep terrain and early season hazards like exposed stumps and rocks are still to watch for. Professionals are still mindful of a facet/crust layer near the base of the snowpack. Although triggering it has become unlikely, it may be possible from a thin-spot trigger point or with a very heavy load (e.g. cornice fall).

Regions covered