Avalanche Forecast

Issued: Jan 27th, 2016 4:06PM

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

brian webster, Parks Canada

Banff Yoho Kootenay.

New snow and strong winds forecast for Thursday. Heads up for changing conditions.

Summary

Weather Forecast

On Thursday strong westerly winds and 10-15 cm of snow along the divide are forecasted. Freezing levels to be near 1900 m. Friday brings a cooling trend with light winds and isolated flurries.

Snowpack Summary

Strong west and SW winds have scoured windward aspects in alpine and and created fresh windslabs in lee terrain at and above treeline. 20-50 cm of snow over-rides the January 6th surface hoar/facet layer which is still reactive in pit tests. This layer is most prominent and reactive in the Kootenay region. A rain crust exists below 1500 m.

Avalanche Summary

On Wednesday Sunshine Village Ski Resort reported fresh wind slabs that were reactive to ski-cutting up to Class 1.5.Monday's avalanche control work in Kootenay resulted in widespread avalanches between size 2 and 3 with fracture lines ranging from 25-50 cm deep failing on the Jan 6th layer of surface hoar and facets.

Confidence

Problems

Wind Slabs

With the incoming wind and precipitation, we can expect touchy conditions on lee features at treeline and above. These windslabs may triggered persistent slabs resulting larger avalanches.

Use caution in lee areas. Recent wind loading has created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

The new snow is settling into a 20-50 cm slab above the Jan. 6th surface hoar and facet layer. This layer is most reactive where there is a thicker slab and buried surface hoar (between 1500 and 2000m in Kootenay).

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Jan 28th, 2016 4:00PM