Avalanche Forecast

Issued: Apr 26th, 2013 4:00PM

The alpine rating is considerable, 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.

A robust wind event with varying snow amounts will occur this weekend making for the possibility of natural avalanches at upper elevations. Watch locally for wind slab development. SH

Summary

Weather Forecast

Strong to extreme West winds Saturday (85-100+kmh) with incoming snow of 20-25 cm in the alpine along the divide. Much less snow is expected in the Banff region. Freezing levels to 1900m . Continued windy conditions Sunday with some light snow. Monday we will see a cooling trend.

Snowpack Summary

Very warm and windy conditions Friday with no overnight freeze up to 2500m. Variable wind slabs in alpine regions sit over a variety of harder surfaces and a generally well settled midpack.

Avalanche Summary

Limited observations Friday but no new avalanches reported.

Confidence

Forecast snowfall amounts are uncertain on Saturday

Problems

Wind Slabs

Previous winds created areas of wind slab in open areas above 2200 m. Watch for touchy wind slab development at treeline and above Saturday with incoming snow and wind. These will be easiest to trigger where they overly harder surfaces and crusts.

Use caution in lee areas in the alpine. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

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.

Be cautious of sluffing in steep terrain.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Apr 27th, 2013 4:00PM