Avalanche Forecast

Issued: Jan 11th, 2014 4:00PM

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

Grant Statham, Parks Canada

Banff Yoho Kootenay.

An avalanche cycle is occurring right now as 30-40cm of storm snow and strong winds have overloaded the weak snowpack. The winds are raking the mountains, and widespread avalanche activity was observed today. The cycle continues through Monday.

Summary

Weather Forecast

The storm pattern will continue with a slight break Saturday night and Sunday morning.Â The models are showing another 10-15 cm of snow by Monday, combined with very strong winds from the west.Â Temperatures will remain cool, with Sunday's high being -11.

Snowpack Summary

20-40 of storm snow has fallen across the forecast region over the last 36-hours, combined with a warming trend and strong to extreme winds from the SW. Widespread windslabs exist in all open areas, overlying a weak and facetted snowpackÂ Expect leeward areas to have upwards of 100cm of drifted windslabs.

Avalanche Summary

Widespread avalanche activity today up to size 3 including both Bourgeau Left and Right waterfalls over the climbs, Healy Creek, Cascade Mountain, Corral Creek and Eagle Basin. This avalanche activity is forecast to continue on Sunday.

Confidence

Problems

Deep Persistent Slabs

The storm has overloaded the weak and facetted snowpack, and large natural avalanches are being observed. Active deep persistent slab conditions like this are dangerous; avoid avalanche terrain for the next few days - time for good snow in the trees.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

2 - 3

Storm Slabs

20-40 cm of storm snow has fallen across the forecast region, creating unstable snow in the surface layers from both new snow and wind. Expect deep windslabs in leeward areas due to extensive wind loading.

Avoid freshly wind loaded features.Use caution in lee areas in the alpine and treeline. Recent storm snow has formed touchy slabs.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Jan 12th, 2014 4:00PM