Avalanche Forecast

Issued: Mar 31st, 2018 4:00PM

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

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

Great ski quality to be had, but check for instabilities in the upper snowpack before venturing into bigger terrain. Avalanche control on Mt. Stephen and Mt. Field tomorrow (Sunday), no activities on these peaks during that time.

Summary

Weather Forecast

5 cm of snow is expected Sunday with S winds moving into the moderate range aloft. Winds will shift to the NE on Monday. Temperatures will stay cool on Sunday with little solar input.

Snowpack Summary

20-30cm of snow (50cm reported on Wapta!) on Friday with W winds have formed isolated wind slabs in lee features. The March 15 sun crust is down 30-50cm on solar aspects and has produced isolated activity over the past few days.The mid- pack and basal layers have been dormant, but shallow facetted snowpack areas are still worth treating cautiously.

Avalanche Summary

Avalanche control on Mts. Bourgeau and Whymper Saturday saw mixed results, with some size 2 wind slabs being triggered, but many bomb holes as well.Â Lake Louise ski hill was reporting 2 size 2 avalanches initiated with explosives that were on the March 15 sun crust.Â Recent cornice falls have produced the same sorts of results.Â

Confidence

Due to the number and quality of field observations

Problems

Wind Slabs

The new snow Friday arrived with strong SW winds but so far wind slabs haven't been observed to be widespread. Winds may go into the moderate range on Sunday with plenty of loose snow to push around. Watch locally for their formation.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

Still some observations of avalanches reported today by Lake Louise ski hill on the March 15th sun crust now buried 30-50cm deep. Dig down to see if the crust exists and its bond to the snow above.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Apr 1st, 2018 4:00PM