Avalanche Forecast

Issued: Dec 13th, 2012 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Great skiing can be found in wind sheltered terrain, especially below between 1750-2500 metres. (LP)

Summary

Weather Forecast

For the next few days leading into the weekend, expect seasonal temperatures (-8 to -13)Â and the occasional snow flurry bringing light amounts of snow.Â Moderate West to North West winds will add to the chill and may add to the alpine surface windslab issue.

Snowpack Summary

Variable surface wind slabs have been found in immediate lee ridge features, as well as open terrain above 2800m. In sheltered locations, very good skiing can be found from 2500m to as low as 1750m. Lower than that and things get a bit thin . A well-settled mid-pack sits atop the Nov 6 rain crust, which is starting to break down in some locations.

Avalanche Summary

A couple of cornice triggered size 1-1.5 slab avalanches, 20-40 cm thick, in the last 24 hours above the Bourgeau left ice climb (SE asp) near Sunshiine.Â They ran quite far for their mass, but stopped about 150 m above the climb.Â No other new avalanches reported today.

Confidence

Problems

Wind Slabs

The wind slabs from earlier this week seem to be isolated to ridge lee features and high, open alpine terrain. In the Yoho area soft slabs were only found at ridge-top. Likely there was more wind on the Wapta & along Hwy 93 North.

Be careful with wind loaded pockets while approaching and climbing ice routes.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Deep Persistent Slabs

Large planar faces or steeper, convex features that have been recently wind-loaded should still be given a miss due to this lingering problem.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 14th, 2012 4:00PM