Avalanche Forecast

Issued: Nov 22nd, 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 Storm Slabs.

snow safety, Parks Canada

Banff Yoho Kootenay.

The potential for large skier triggered avalanches continues to exist. Limit exposure to large alpine features and be conservative until things settle out. At treeline and below the snowpack is shallow and many early season hazards are present. CJ

Summary

Weather Forecast

The next few days look like a mix of sun and cloud with generally light winds out of the W and no significant precipitation. Warmer temperatures will be present with alpine temperatures approaching the freezing mark at times.

Snowpack Summary

30 to 50 cm of low density storm snow was received earlier in the week. This is slowly settling out into a soft slab over a weak layer of basal facets. The Oct 27 rain crust is present near the ground in many alpine areas, especially on North aspects and continues to provide a good sliding layer. Wind affect in open areas at treeline and above.

Avalanche Summary

Several explosive triggered storm slabs up to size 3, sliding on the Oct 27th rain crust were reported today in the Sunshine and Lake Louise ski areas. Natural activity has slowed down however the possibility for human triggering of the weak layers at the bottom of the snowpack remains high.

Confidence

Problems

Wind Slabs

While the winds have calmed down the potential for triggering existing wind slabs remains especially in alpine areas. These slabs have the potential to step down into the weaker basal facets and the October crust resulting in larger avalanches.

Be aware of the potential for wide propagations due to the presence of hard windslabs.Avoid freshly wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Storm Slabs

The recent snow is settling into a cohesive slab and the natural and explosive triggered avalanche activity in the last couple days confirms the potential for large slides on the basal facets and Oct 27 crust.

Use caution in lee areas in the alpine and treeline. Recent storm snow has formed touchy slabs.Be aware of thin areas that may propogate to deeper instabilites.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Nov 23rd, 2013 4:00PM