Avalanche Forecast

Issued: Dec 16th, 2016 3:44PM

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

Avalanche Canada rbuhler, Avalanche Canada

Wind slabs continue to be the primary concern. Watch for signs of recent wind loading and use extra caution in wind exposed terrain.

Summary

Confidence

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

Weather Forecast

The ridge of high pressure that has been producing cold, dry conditions is breaking down and allowing active weather systems into the region starting late Saturday. 1-3 cm of snowfall is expected on Saturday with strong northwest winds and treeline temperatures around -10C. Another 5-15 cm of snowfall is forecast between Saturday evening and Sunday afternoon. Alpine winds should remain strong on Sunday but are forecast to shift to the southwest. Treeline temperatures are expected to be around -5C on Sunday. Another period of snowfall with strong winds is currently forecast for Sunday overnight and into Monday.

Avalanche Summary

No recent avalanches have been reported in this region. Ongoing strong winds have formed hard wind slabs in exposed terrain which may still be reactive to human triggering in isolated areas. New winds slabs are expected to form over the weekend with the forecast for light snowfall and strong alpine winds.

Snowpack Summary

Clear skies and strong outflow winds have created a variety of snow surfaces including scouring and hard wind slabs in exposed areas.  Faceting of the upper snowpack and surface hoar formation has been reported in sheltered areas. The new snow is expected to bond poorly to this interface. According to reports near Smithers, there is a layer of surface hoar down 40-50 cm, though no recent activity has been reported on this layer. A thick rain crust that formed in early November is now buried 50-60 cm deep. Early season snowpack observations are still very limited in the region, but reports suggest the average snowpack depth is 50-90 cm at treeline and 120 cm or greater in the alpine.

Problems

Wind Slabs

An icon showing Wind Slabs
Recent strong outflow winds have formed hard wind slabs. On Saturday, strong winds from the opposite direction with new snowfall will likely form new wind slabs. Use caution on all aspects in wind affected terrain.
Use ridges or ribs to avoid pockets of wind loaded snow.Recent wind has varied in direction so watch for wind slabs on all aspects.Avoid slopes where the snow feels stiff or slabby.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Dec 17th, 2016 2:00PM

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