Avalanche Forecast

Issued: Dec 22nd, 2016 5:51PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Avalanche Control planned for Kootenay Park on Friday. Please no skiing on Mt Whymper or on the Simpson avalanche paths.

Summary

Weather Forecast

Mainly cloudy with isolated flurries for Friday. The strong winds that we have been experiencing over the last few days should decrease on Friday becoming light to moderate from the west. Light flurries forecast for Saturday and the sun should come out for Christmas Day.

Snowpack Summary

The storm has brought us 15 to 30 cm of new snow, with more falling on the West side of the Divide. Moderate to strong winds have created a windslab that overlays a very loose faceted snowpack. The windslab/facet interface was touchy in avalanche control work on Wednesday. The Nov crust is 30-80cm deep, and is not currently reactive.

Avalanche Summary

Explosive control on Wednesday resulted in several avalanches up to Class 3 on Mt. Bosworth. One slope failed when the explosive bag hit the slope. The failure layer is the windslabs on the facets. Not many naturals reported or seen, except for a size 2 over Pilsner climb area on Mt Dennis also on Wednesday.

Confidence

Problems

Wind Slabs

New snow and strong winds have created a wind-slab on exposed slopes in the alpine and tree line that could be easily skier triggered. This new slab sits over a very faceted snowpack creating a weak interface.

Be careful with wind loaded pockets while approaching and climbing ice routes.Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Valid until: Dec 23rd, 2016 4:00PM