Avalanche forecast

Northwest Coastal

Dec 9 – 10, 2014Avalanche Canada
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Avalanche danger

Thu
Fri
Alpine
4 · High
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Heavy loading from snow, wind, and rain is likely resulting in natural avalanche activity.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    2–5
    Heavy storm snow is expected to bond poorly and overload deeper weaknesses in the snowpack. Extreme southerly winds could also create dense wind slabs well below ridge tops.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2
    Expect heavy loose wet sluffs in steep open terrain and in gullies.

Confidence

Fair - Due to the number of field observations

Weather Forecast

On Wednesday expect another 5-15 mm of rain (or cm of snow) as freezing levels to drop as low as 1500 m in the southern part of the region or lower up north, and alpine winds continue to blow strong from the southeast. Thursday is looking mostly dry as freesing levels hover around the 1000-1500 m mark and alpine winds ease off throughout the day. A bit more snow could arrive on Friday with up to 10 cm in some areas accompanies by moderate to strong southwesterly alpine winds and freezing levels dropping below 1000 m.

Avalanche Summary

Reports from Monday include several explosive-triggered storm and wind slab avalanche up to Size 2.5 at all elevations and on all aspects. The slabs were no deeper than 35 cm and failed on old facets under recent storm snow, or right on the ground in shallow snowpack areas below treeline.

Snowpack Summary

Heavy rain is saturating the upper snowpack and resulting in wet, loose, and cohesionless surface snow as high as alpine elevations in the southern part of the region. While in the alpine and as low as treeline elevations further north wet snow and wind has formed new storm slabs and is overloading previous weaknesses buried within the snowpack, such as the mid-November crust-facet layer.

Regions covered