Avalanche Forecast

Issued: Feb 19th, 2019 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 Loose Dry.

snow safety, Parks Canada

Banff Yoho Kootenay.

Dry good ski conditions continue, watch for small amounts of loading from light to moderate winds which will produce windslabs in the alpine and treeline.

Summary

Weather Forecast

For Wednesday we expect Light to Moderate Northerly winds switching to North East in the afternoon, temperatures from -15 to -5 and trace amounts of new snow.

Snowpack Summary

30 to 50 cm of snow has fallen since Feb 2. Recent new snow has been affected by Light to Moderate westerly winds. Cold conditions continue promoting faceting of the snowpack. 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

Several reports of both skier triggered wind slabs and loose dry avalanches have been noted this past week. Generally these avalanches have been small (size1-2) but have been running far, entraining the loose faceted surface snow.

Confidence

Due to the number and quality of field observations

Problems

Wind Slabs

New snow and Light to Moderate westerly winds have created wind slabs. These slabs have yet to produce anything larger than a size 2.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

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.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Feb 20th, 2019 4:00PM