Avalanche Forecast

Issued: Feb 24th, 2016 6:16PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Persistent Slabs, Loose Wet and Wind Slabs.

brian webster, Parks Canada

Banff Yoho Kootenay.

Pay attention to the effects of the sun as the day warms up. Many loose wet avalanches were observed on Wednesday afternoon

Summary

Weather Forecast

The upper ridge will remain intact through Friday. Expect light winds, good overnight freezes and significant warming during the day. Freezing levels will be around 1800-2000 m. Light flurries expected for Saturday.

Snowpack Summary

Sun crusts on solar aspects. Recent wind slabs and cornice growth in the alpine with 30-50 cm of snow in the last week. A 50-100 cm slab overlies the January 6 persistent weak layer of surface hoar, facets and sun crust which has had lots of avalanche activity on it in the last week. The lower snowpack is facetted and weak in thin snow pack areas.

Avalanche Summary

On Tuesday a small sluff ran over the French Reality Ice Climb in Kootenay and triggered a 100 cm deep slab on the slope below. On Monday a cornice triggered a slab on an east aspect in the Bow Hut area. Also on Monday a skier was caught and partially buried in a size 2 slab triggered on a west aspect of Richardson's Ridge at Lake Louise.

Confidence

Problems

Persistent Slabs

50-100 cm of snow overlies the Jan 6th layer of surface hoar, facets and sun crust. Numerous avalanches have been triggered on this layer in the last week. In thin snow pack areas, some of these avalanches have stepped down to the ground.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Avoid paths that have not avalanched recently.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Loose Wet

Relatively high freezing levels and strong solar inputs will create loose wet snow avalanches in the afternoon.

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Wind Slabs

Be wary of cross loaded features and the lees of ridges where recent moderate to strong W winds have formed wind slabs and developed fragile cornices. Recent wind slab avalanches have also stepped down to the persistent weak layer and the ground.

Use caution in lee areas. Recent wind loading has created wind slabs.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Feb 25th, 2016 4:00PM