Avalanche Forecast

Issued: Feb 21st, 2014 4:00PM

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.

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

We are strongly urging people to be very conservative this weekend with their terrain choices. This is due to the nature of the weak layer currently in the snowpack. SH

Summary

Weather Forecast

Expect flurries with local amounts of 5cm on Saturday. Temperatures will be in the -15 to -20 range over the weekend. Light gusting moderate NW winds for Saturday.

Snowpack Summary

30-70cm of recent storm snow is settling and overrides the Feb10th interface. A poor bond persists at this interface and many avalanches have been observed on this layer over the past week. 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 today produced avalanches to sz 2.5, likely failing on the Feb.10th interface.

Confidence

Due to the number of field observations on Friday

Problems

Persistent Slabs

There is still a poor bond between the storm snow and the Feb.10 layer of facets and surface hoar. This interface is still very susceptible to human triggering.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Wind Slabs

Wind slabs have been forming at higher elevations from SW winds over the last few days.

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

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Feb 22nd, 2014 4:00PM