Avalanche Forecast

Issued: Nov 14th, 2012 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Little change until Saturday. Decent skiing in sheltered alpine and treeline features where the crust carries. SH

Summary

Weather Forecast

Light to moderate W winds Thursday and Friday with freezing levels to 1500m during the day and little to no precip. Strong to extreme SW winds on Saturday with the possibility of some snow. We could see a spike in hazard through Saturday.

Snowpack Summary

25-35cm of recent storm snow overtop of Nov. 6 crust, which can be found to 2500m and disappears around 2700m. The Sunshine ski area plot (2100m) showed laminated crusts down 30cm(Nov.6) to 45cm. Resistant planar compression results on Nov.6.

Avalanche Summary

No new natural avalanches observed today from field trips in the Sunshine back country and road patrols throughout Yoho and Kootenay.

Confidence

on Thursday

Problems

Wind Slabs

Various hard and soft wind slabs (20-50cm thick) in the alpine are sitting on the Nov.6 crust and producing moderate shears in compression tests. Slabs becoming less reactive but still possible for a skier to trigger these in steep lee terrain

Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

Deep slabs size 2-3 have been noted on isolated steep alpine slopes over the past week. Failure plane was at the bottom of the snow pack on firn or glacier ice. No new have been reported these last few days but are still possible in the high alpine.

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

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Nov 15th, 2012 4:00PM