Avalanche Forecast

Issued: Apr 24th, 2013 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.

chris gooliaff, Parks Canada

Banff Yoho Kootenay.

Watch for the bond between wind slabs and loose powder to harder bed surfaces below before stepping into steep alpine terrain features.

Summary

Weather Forecast

Clouds will slowly move into the area, along with increasing winds from the W/NW. We may see light amounts of snow later in the day, but no real accumulations until Friday/Saturday. Freezing levels should hold around 2000m for Thursday/Friday.

Snowpack Summary

Cool temp's and thin high cloud kept crusts intact today into the afternoon. Wind slabs can be found in steep alpine features, especially near ridge crests. These slabs can be triggered on all aspects, especially S where they overly harder crusts. Loose snow avalanches on N aspects over harder bed surfaces in the alpine were seen Tuesday.

Avalanche Summary

A field team saw heavy sloughing with ski cutting in a steep North aspect (2800m) in the Lake O'Hara region. This was overlying a harder bed surface. Numerous other avalanches to size 1.5 have been observed in steeper terrain, especially on Southerly aspects.

Confidence

Problems

Wind Slabs

Moderate winds have created areas of thin wind slabs in open areas above 2200 m. These slabs were more sensitive to triggering on southerly aspects where they overly a smooth crust, but are also a concern on northerly aspects.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Loose Dry

Watch for heavy sloughing where powder overlies harder bed surfaces. In steep terrain, this could push you over a cliff or into a terrain trap.

On steep slopes, pull over periodically or cut into a new line to manage sluffing.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 25th, 2013 4:00PM