Avalanche Forecast

Issued: Mar 5th, 2018 4:59PM

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.

conrad janzen, Parks Canada

Banff Yoho Kootenay.

Good skiing and travel conditions continue, though the sun is beginning to pack a punch on S aspects. With the winds moving the recent storm around up high we have left the alpine rating at Moderate for another day.

Summary

Weather Forecast

Tuesday should see treeline temperatures rising from -15 to -5'C during the day. Alpine winds are expected to be in the light to moderate range out of the West. Some cloud cover and light flurries are forecasted with occasional sunny breaks.

Snowpack Summary

Variable amounts of low density storm snow (10-25 cm) now sit on top of a supportive mid-pack. The higher amounts of storm snow are in the southern region. Light wind effect in the alpine. Sun crust forming on some steep solar aspects. The deeper facet layers down 80-150 cm remain weak but are presently difficult to propagate.

Avalanche Summary

Sluffing and thin storm slabs up to size 1.5 were observed in steep alpine terrain today, including some solar triggered sluffs out of rocky areas. One small skier triggered wind slab was reported on a cross loaded feature in the Lipalian Chutes outside the Lake Louise ski area. One size 2 natural avalanche was observed, possibly cornice triggered.

Confidence

Due to the number and quality of field observations

Problems

Wind Slabs

Increasing alpine West winds are forming wind slabs in lee areas near ridge crests. In steep unsupported terrain skier triggering is possible.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Loose Dry

This problem is more pronounced in the Southern parts of the forecast region that received more storm snow. It will be particularly prevalent in steep confined gullies, and/or where the old snow below the storm snow is weak and facetted.

On steep slopes, pull over periodically or cut into a new line to manage sluffing.The volume of sluffing could knock you over; choose your climb carefully and belay when exposed.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Mar 6th, 2018 4:00PM