Avalanche Forecast

Issued: Dec 6th, 2015 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs.

tim haggarty, Parks Canada

Banff Yoho Kootenay.

Stormy weather is expected to affect the region over the next few days. Slab formation has begun over the December 3 interface and we will be closely watching how the incoming snow bonds to this highly variable layer.

Summary

Weather Forecast

A series of systems will bring moderate amounts of precip in several pulses to the region through Thursday. Moderate to strong westerly winds will continue in the alpine and freezing levels look like they should peak Tuesday with the influence of the south westerly flow.

Snowpack Summary

The Dec 3 interface is now buried by 10-20cm in the alpine. This interface consists of facets BTL, widespread wind effect above TL, suncrusts on steep S and SW aspects, and surface hoar up to 20 mm found in some locations up to 2000m. South and Southwest winds in the moderate range are building soft slabs in the lee of alpine features-.

Avalanche Summary

Small windslabs local to ridgecrests are reactive to skier traffic in the alpine and at treeline.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Wind Slabs

Small wind slabs are forming in the immediate lee of prominent features and ridgelines. Areas further to the north have seen, and expected to see, larger snow inputs so greater slab development can be expected in those regions.

Be cautious as you transition into wind affected terrain.Use caution in lee areas. Recent wind loading has created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 7th, 2015 4:00PM