Avalanche Forecast

Issued: Mar 7th, 2014 6:43PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is considerable. Known problems include Persistent Slabs and Wind Slabs.

snow safety, Parks Canada

Banff Yoho Kootenay.

Several skier triggered avalanches over the past 3 days size 2-2.5 in KNP and Sunshine area, see the forecast details. Stick to conservative lines without over head hazard. LP

Summary

Weather Forecast

West winds to increase to strong over night & through the weekend bringing snowfall accumulations of up to 30 cm.Â Most of the snow will occur on Sunday along the Wapta & the Divide.Â Alpine temperatures will be warm (-2 to -5 range).Â The hazard will rise through the weekend.Â Skies will clear Monday as a high pressure moves into the region.

Snowpack Summary

Sunshine, Kootenay and Yoho areas have received up to 75 cm of storm snow since March 2. Lesser amounts of 30-40 cm around Lake Louise and Bow Summit. 40-100cm over the reactive Feb 10 interface of facets,surface hoar,suncrust . Fresh wind slabs up to 40-60 cm deep in the alpine are reactive to skier control.

Avalanche Summary

Over the past three days there have been several skier triggered size 2-2.5 avalanches on the Feb 10th interface in steep terrain or steep convexities in Kootenay and in the Sunshine area below treeline. Avalanche control on the sunshine road produced results up to size 3. Less avalanche activity has been observed in the Louise group.

Confidence

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

Problems

Persistent Slabs

This layer is especially touchy around Sunshine and in Kootenay on steep features at treeline and below. There have been several skier triggered avalanches to size 2 in past 36 hours and explosive triggered avalanches to size 3 today.

Avoid open slopes with any steepness over 30 degrees.Avoid steep, open glades in the forest.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

2 - 3

Wind Slabs

There are thin windslabs from the last storm on lee features that are reactive to explosives (size 1-2). Expect new windslabs to develop with incoming snow and wind over the weekend.

Be cautious as you transition into wind affected terrain.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Mar 8th, 2014 4:00PM