Avalanche Forecast

Issued: Dec 12th, 2012 9:18AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Persistent Slabs and Wind Slabs.

Avalanche Canada ccampbell, Avalanche Canada

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain on Saturday

Weather Forecast

Thursday: Cloudy with light snow starting in the afternoon, freezing levels remaining in valley bottoms, and light westerly alpine winds becoming moderate to strong southwesterlies with the onset of precipitation. Friday: Light snow tapering off throughout the day with 5-10cm total since Thursday, light northwesterly winds and freezing levels as high as 600m. Saturday: Moderate snowfall, strong southwesterly winds and freezing levels rising as high as 600m.

Avalanche Summary

No new avalanche activity has been reported. Expect fresh wind slabs and loose surface snow to be sensitive to human triggers.

Snowpack Summary

Recent winds have been redistributing the low density surface snow onto leeward slopes creating thin wind slabs that have been giving moderate compression tests results. Surface hoar buried at the end of November recently gave moderate to hard but sudden results in compression tests where it has been found as large as 10mm down 75-120cm, or shallower in the Rossland Range where it more of a concern. On a southwest aspect at 2020m in a shallow faceted snowpack area of Kootenay Pass, facets sitting on a rain crust recently gave moderate but resistant compression test results down 30-35cm. Recent reports suggest that the early November facet/crust deep persistent basal weakness has been producing inconsistent, but occasionally sudden snowpack test results and remains a concern. Keep this on your radar, especially when traveling in areas at higher elevations that have a smooth ground cover where the existing crust is uniform and consistent.

Problems

Persistent Slabs

An icon showing Persistent Slabs
Slopes that roll over such that the slab is unsupported from below. Particularly in areas with a shallower snowpack.
Choose well supported terrain without convexities.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 5

Wind Slabs

An icon showing Wind Slabs
A soft slab on the surface is stiffening with with continued settlement and wind-exposure, and may be triggered by light additional loads like a skier or rider.
Be cautious as you transition into wind affected terrain.>Avoid freshly wind loaded features.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 13th, 2012 2:00PM