Avalanche Forecast

Issued: Dec 6th, 2016 3:29PM

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

Avalanche Canada triley, Avalanche Canada

Wind slabs continue to be reactive to skiers in loaded lee pockets at higher elevations. The new storm is expected to increase avalanche danger on Friday.

Summary

Confidence

Moderate - Due to the quality of field observations on Tuesday

Weather Forecast

Mostly clear with some valley cloud on Wednesday morning. Light northeast winds becoming light northwest by Wednesday evening. No new snow expected and alpine temperatures around -20. Light snow starting Thursday evening combined with moderate southwest winds and alpine temperatures around -15. Overcast with light snow on Friday with alpine temperatures closer to -10. 

Avalanche Summary

On Sunday, explosives and ski cutting in the north of the region produced wind slab avalanches up to size 2. These wind slabs were on northerly aspects and were typically 10-20cm thick but one was reported to be up to 40cm thick. On Tuesday, the wind slabs that formed over the weekend are expected to remain reactive to human-triggering. These wind slabs are expected to be most reactive on north through east aspects in the alpine.

Snowpack Summary

The weekend storm system brought 20-40cm of new snow to the region with strong southwest winds in the alpine. The resulting wind slabs are thickest and most reactive on north and east aspects in wind exposed terrain. The mid-November crust is typically down 50-80cm. Weak facet crystals are reported to be forming above and below this crust layer. With the ongoing cold weather, continued faceting is expected around this layer and it has the potential to create a persistent slab problem in the future.

Problems

Wind Slabs

An icon showing Wind Slabs
Lingering wind slabs from the weekend may still be reactive to human triggering in leeward features.
Use ridges or ribs to avoid pockets of wind loaded snow.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 7th, 2016 2:00PM