Avalanche Forecast

Issued: Jan 19th, 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.

william lawson, Parks Canada

Banff Yoho Kootenay.

Moderate danger means heightened avalanche conditions where human triggered avalanches are possible. Be cautious when traveling in complex terrain.

Summary

Weather Forecast

Trace amounts of precipitation expected through the weekend, winds will remain in the light to moderate rang and temperatures steady between -8 to -12.

Snowpack Summary

Newly formed windslabs on immediate lees at alpine and treeline elevations. In sheltered areas the upper snowpack consist of 20-30cm of soft slab over the Jan 6 surface hoar, this layer has been reactive in test results. The Dec 15 layer is still a concern 40-60 cm down. Much of the snowpack is facetted with little structure below treeline.

Avalanche Summary

Minimal avalanche activity reported today, Lake Louise ski patrol reported small skier triggered windslabs from loaded pockets at ridge crest.

Confidence

Problems

Wind Slabs

Recent snow and accompanying winds have created windslabs at alpine and treeline elevations. Due to variable winds in the alpine expect the spacial distribution of this problem to be widespread.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

The Dec 15 layer continues to cause some uncertainty with forecasters. Few avalanche observations have been reported on this instability, though widespread cracking and whumphing is still occurring when traveling in the backcountry.

Choose conservative lines and watch for clues of instability.Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 20th, 2018 4:00PM