Avalanche Forecast

Issued: Feb 17th, 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.

aaron beardmore, Parks Canada

Banff Yoho Kootenay.

Watch for new windslabs in alpine lee areas and loose dry avalanches in steep terrain. Ski quality is currently excellent.

Summary

Weather Forecast

Valley temperatures will vary between -5 and -20 for the next 3 days. Clear skies are expected on Monday with light North wind. A slight increase in cloud and wind (up to moderate west) is expected on Tuesday. Overall, minimal weather inputs that will impact the danger rating.

Snowpack Summary

30 to 50 cm of snow has fallen since Feb 2. This has been affected by variable winds, isolated periods of 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

Numerous loose dry avalanches and wind slabs up to size 2 were observed today on a flight from Banff to the Wapta Icefields. The wind slabs appeared to bit between 10 and 20cm thick. Additionally, a skier triggered avalanche was reported on the MIN near Paget Glades today, no injury or lost gear reported.

Confidence

Problems

Wind Slabs

New snow and some light North wind have created new soft windslabs in the last 24 hours. As of today these slabs were not producing 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.

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.

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.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Feb 18th, 2019 4:00PM