Avalanche Forecast

Issued: Apr 23rd, 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.

Snow Safety, 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. Expect some sun Wed. so watch for increasing hazard in the afternoon. SH

Summary

Weather Forecast

Moderate gusting strong NW winds at ridgetop Wed. with good overnight recovery expected and no new snow. We may see a jump in hazard on Friday due to strong winds and possibly some new snow West of the divide.

Snowpack Summary

Cool and mainly cloudy conditions 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

Due to the number and quality of field observations on Wednesday

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 which 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 24th, 2013 4:00PM