Avalanche Forecast

Issued: Jan 20th, 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.

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

Summary

Weather Forecast

Highs of -5 to -8C at valley bottom and -10 to -12C at upper elevations Sunday. 3000m winds will be strong from the SW and light at valley bottom. Only a couple few cm of snow is expected along the divide and less to the East.

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, which 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

No new avalanches observed or reported today

Confidence

Problems

Wind Slabs

Recent winds and snow have formed slabs in immediate lees. Pay attention to the surface texture and local wind transport as these will be the biggest indicator of their formation.

Avoid freshly wind loaded features.

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.

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

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Jan 21st, 2018 4:00PM