Avalanche Forecast

Issued: Dec 15th, 2016 3:38PM

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

Avalanche Canada cam_c, Avalanche Canada

Beware of wind-loaded and sun-exposed slopes where the recent storm snow has settled into touchy slabs.

Summary

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

On Friday expect a mix of sun and cloud with moderate northerly winds and alpine temperatures around -15. Mainly cloudy for Saturday with moderate to strong northwesterly winds and alpine temperatures in the -10 to -15 range. Sunday should also be mainly cloudy with a chance of flurries late in the day. Ridgetop winds are expected to increase to strong westerlies and alpine temperatures increasing to -10.

Avalanche Summary

No new avalanches have been reported, but expect the recent storm snow to be reactive to light triggers in areas where it has settled into a cohesive slab, such as lee slopes near ridgecrests and terrain breaks and sun-exposed slopes.

Snowpack Summary

Surface hoar is growing and surface snow is faceting. 30-70 cm of low density snow recently buried the previous variable snow surface, including hard wind pressed or scoured areas, old wind slabs, weak faceted snow, or small surface hoar. Wind slabs that have formed in response to southwest winds during the storm, or subsequent northerly winds, are sensitive to light triggers with recent reports of easy hand shears and cracking around skis. In the Duffey Lake area, recent snowpack tests gave moderate sudden planar results down 36 cm on buried surface hoar. Weaknesses have also been found within the recent storm snow with reports of moderate snowpack test results on preserved stellars down 48cm in the Coquihalla Pass area. The widespread mid-November crust typically down around a metre. Recent snowpack tests have shown the crust to be unreactive, but it could become a problem in shallow alpine start zones.

Problems

Wind Slabs

An icon showing Wind Slabs
In the south of the region, snowfall accumulations are enough that storm slabs may developed. The new snow is expected to be bonding poorly to the old surface. Throughout the region, expect wind slabs on all aspects in exposed terrain.
Use ridges or ribs to avoid pockets of wind loaded snow.Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 16th, 2016 2:00PM

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