Avalanche Forecast

Issued: Dec 1st, 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 Persistent Slabs.

Brad White, Parks Canada

Banff Yoho Kootenay.

Good skiing can be found at sheltered treeline elevations. Watch for sloughing in very steep gullies if winds pick up. SH

Summary

Weather Forecast

2-5cm Sunday with mainly light-mod. S-SW winds forecast. and freezing levels up to 1500-1600m . Alpine winds may spike Sunday evening in to Monday.

Snowpack Summary

Bow Peak Hwy93 N @2400m HS 95. CTHRP results on Nov6 CR prominent 20cm off of ground. 5cm HN24 in most locations being redistributed mainly from SW winds forming thin wind slabs on lee aspects at ridgetop. Facetting of snowpack winning in many areas

Avalanche Summary

When winds picked up there was a sz 1.5 sluff out of steep ski terrain in the Granddaddy couloir on Bow Peak. Not much mass but would have flushed a skier or climber. Lake Louise ski hill had no results bombing in previously uncontrolled terrain.

Confidence

Wind effect is extremely variable

Problems

Wind Slabs

Shifty winds Sat. created thin wind slabs near ridge crests. These will increase in size and sensitivity with continued wind transport.

Caution in lee and cross-loaded terrain near ridge crests.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

The Nov 6 rain crust is down 50-90 cm, and this is still a significant layer in the snowpack. Evaluate this layer carefully prior to entering steeper/bigger terrain. Weakening of this layer through facetting has been the general trend.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 2nd, 2012 4:00PM