Avalanche Forecast

Issued: Dec 20th, 2016 5:05PM

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

mbender, Avalanche Canada

South Coast Inland.

The last few days' new snow sits on a variety of potential weak sliding layers. As the storm snow settles in the coming days, it will be critical to evaluate the bond between new and old snow layers.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Wednesday: Cloudy with some sunny periods/ Moderate southwest wind / Alpine temperature -3Thursday: Flurries, accumulation 10cm / Moderate to strong southwest wind / Alpine temperature -4 Friday: Isolated flurries/ moderate north wind / Alpine temperature -5

Avalanche Summary

There are no new recent reports of avalanche activity, however I would suspect there to be continued potential for skier and rider triggering with the recent new snow, strong winds at upper elevations and a possible weak bond at the storm/old snow interface.

Snowpack Summary

30-60cm new snow overlies the previous variable snow surface from last week, which includes hard wind pressed or scoured areas, old wind slabs, weak faceted snow, or surface hoar. New wind slabs that have formed in response to southwest winds. In the Duffey Lake area, recent snowpack tests gave moderate sudden planar results down 50 cm on buried surface hoar. The widespread mid-November crust is typically down approximately 1 metre. Recent snowpack tests have shown the crust to be unreactive, but it could become a problem in shallow alpine start zones.

Problems

Storm Slabs

30-50cm of new snow sits on a variety of potential weak sliding layers.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Wind Slabs

Moderate to strong southwest winds have created wind slabs in the lee of terrain features

Be cautious as you transition into wind affected terrain.Use ridges or ribs to avoid pockets of wind loaded snow.

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 21st, 2016 2:00PM