Avalanche Forecast

Issued: Feb 16th, 2019 4:00PM

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

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

Conditions are still pretty good with only 5-10cm falling in the last 24 hours under light winds. Watch for pockets of older wind slabs in alpine areas, and sluffing of facetted snow formed from the cold snap in very steep terrain features .

Summary

Weather Forecast

A return to colder temperatures tomorrow with lows around -25C and highs of -15C. Light NE winds for the next 2 days and no new snow.

Snowpack Summary

30 to 50 cm of snow has fallen since Feb 2. This has been affected by variable winds, isolated periods of intense solar radiation and most notably, sustained cold temperatures promoting faceting. Down 30 to 75cm, Jan 17 surface hoar produces sudden planar shears in isolated locations treeline an below. A weak basal snowpack exists in shallow areas

Avalanche Summary

Lake Louise reported a skier triggered hard wind slab which occurred today. The slide was a size 2 that occurred in the alpine with the sliding surface unknown. Some smaller wind slabs were noted on cathedral peak which had occurred in the last 24 hours.

Confidence

Problems

Wind Slabs

Older wind slabs are still active in isolated areas. Watch for pockets of these in steeper alpine areas, as well as below cliff faces where spin drift has formed thicker slabs.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Variable winds may create pockets of wind slab in some unexpected locations.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Loose Dry

A sustained period of cold weather has driven the faceting process in the upper snowpack creating weak, dry surface snow. In steep terrain, these are sensitive to small natural and human triggers and can quickly gain enough mass to affect travelers.

Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.Good group management is essential to manage current conditions safely.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1

Valid until: Feb 17th, 2019 4:00PM