Avalanche Forecast

Issued: Dec 3rd, 2016 4:00PM

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

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

Some new snow and wind will improve ski quality, but really watch for new wind slab development as well as spindrifting in alpine gully features. The first real arctic air is inbound starting Monday.

Summary

Weather Forecast

Another 5-15 cm with moderate Westerly winds are possible by Sunday morning with less amounts in the East. Temperatures will start to cool by Sunday evening as winds die down and we switch to a Northerly arctic flow. Expect temperatures to go sub -20 for the first part of next week.

Snowpack Summary

10-20cm of snow over the last 24 hours with moderate to strong SW winds creating wind slabs up to 30cm thick in lee alpine areas. A mid pack crust is allowing the snowpack to carry travelers fairly well except in shallow areas. We are watching for this crust to weaken but it is not producing avalanches yet.

Avalanche Summary

The Lake Louise region received enough new snow and wind to create fresh wind slabs up to size 2 in lee alpine features. These were reported as touchy in the morning but will settle out quickly. Other areas such as Sunshine ski area were reporting much smaller wind slabs only in the immediate lees of ridge features.

Confidence

Forecast snowfall amounts are uncertain on Sunday

Problems

Wind Slabs

There seems to be quite variable reports of wind slab development, from touchy around Lake Louise to smaller and more stubborn n the Sunshine area. Watch locally for their development.

Be careful with wind loaded pockets while approaching and climbing ice routes.The new snow will require several days to settle and stabilize.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

New snow and wind will mean spindrift in the short term, especially for ice climbers in gullies.

Use caution above cliffs where small avalanches may have severe consequences.Be very cautious with gully features.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Dec 4th, 2016 4:00PM