Avalanche Forecast

Issued: Dec 10th, 2016 3:57PM

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

Light snowfall and moderate wind should continue to develop pockets of wind slab in exposed terrain at higher elevations.

Summary

Confidence

Moderate - Due to the number of field observations on Saturday

Weather Forecast

Light snowfall is expected Saturday overnight and most of Sunday. Models are currently showing around 5-15cm of snowfall by the end of the storm. On Sunday, treeline temperatures are expected to be around -10C and alpine winds are forecast to be moderate from southwest in the morning switching to northwest in the afternoon. On Monday, dry conditions are expected with a mix of sun and cloud. Treeline temperatures are expected to be around -15C and alpine winds should be light to moderate from the northwest. Sunny, dry, and cold conditions are currently expected for Tuesday.

Avalanche Summary

On Friday, ski cutting was producing size 1 loose avalanches in wind loaded terrain features. Continued snowfall on Sunday with moderate winds from a variety of aspects means reactive wind slabs have the potential to form on any aspects in wind exposed terrain.

Snowpack Summary

Light snowfall with moderate winds are burying cold and loose surface snow. Surface hoar growing up to 15mm in size was reported this week, and widespread faceting has occurred in the top 25cm of low density snow. Expect new snow to bond poorly with this interface, especially in deeper wind-loaded pockets. The lower snowpack is settled and strong. A widespread crust that was buried in November can be found 50-100cm deep. Cold temperatures have promoted facet growth around the crust, which could possibly make the layer reactive in shallow rocky start zones. Snowpack depths are 130-160cm at treeline, and significantly less below treeline.

Problems

Wind Slabs

An icon showing Wind Slabs
Shifting moderate winds and light snowfall may develop new wind slabs on various aspects at higher elevations. Wind slabs are expected to continue to be reactive to human triggering in isolated terrain features.
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 11th, 2016 2:00PM

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