Avalanche Forecast

Issued: Feb 22nd, 2014 4:02PM

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

brian webster, Parks Canada

Banff Yoho Kootenay.

Summary

Weather Forecast

A high pressure moving in late Sunday brings a cooling and clearing trend for for the start of next week. Sunday will be sunny with cloudy periods. Alpine temperatures reaching a high of -16. Ridge top winds forecast to be light from the north-west on Sunday moving to light from the north as the high pressure becomes established.

Snowpack Summary

30-70cm of recent storm snow is settling and overrides the Feb10th interface. Field tests today show an easy to moderate shear persists on the storm snow interface. Recent SW winds have created wind slabs in lee alpine terrain. These wind slabs are easily triggered and often step down to the Feb 10th interface.

Avalanche Summary

The natural avalanche cycle seems to have subsided, but skier triggered avalanches (up to class 2) were reported in the Lake Louise on Thursday, and two skier remotes were reported on the moraine approach to Peyto Glacier on Wednesday. Avalanche control on Mt. Whymper yesterday produced avalanches to sz 2.5 failing on the Feb.10th interface.

Confidence

Problems

Persistent Slabs

The storm snow interface down 40-70 cm still producing easy to moderate results. Natural cycle is over but still possible for skiers to trigger this layer.

Avoid unsupported slopes.Avoid open slopes with any steepness over 30 degrees.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Wind Slabs

Recent winds have produced wind slabs in lee alpine terrain. These wind slabs could step down to the storm snow interface resulting in large avalanches.

Be cautious as you transition into wind affected terrain.Use caution in lee areas in the alpine and treeline. Recent storm snow has formed touchy slabs.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Feb 23rd, 2014 4:00PM