Avalanche Forecast

Issued: Jan 30th, 2013 4:06PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

The major concern today is the potential to trigger windslabs in steep unsupported trerrain. In Kootenay another concern is a buried surface hoar layer down 55.

Summary

Weather Forecast

Cool NW flow will give way to a warm westerly flow with the chance of some light snow showrers and mod to strong winds.

Snowpack Summary

In alpine there is 20-25 cm of recent storm snow sitting on previous hard wind slabs and wind pressed snow. Some soft slab development in lee terrain near ridge tops. In shallow snow pack areas the mid-pack is facetting and losing strength. In the south west (Kootenay) there is a buried surface hoar layer down 55 cm that is a concern.

Avalanche Summary

Forecasters observed a size 2 naturally triggered avalanche on a N aspect around 2300m on the Sunshine road in the last 48 hrs. A natural Icefall avalanche ran off the north face of Mt. Stephen today and just covered the train snow shed. A natural 1.5 was observed on the NE slope of Dolomite peak.

Confidence

Problems

Wind Slabs

Isolated wind slabs in steep terrain features may be human triggered or run naturally with slight additional loading.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

Hard slabs from previous high winds have been buried by recent storm snow. These slabs have been unreactive to skier triggering, but new wind loading may awaken them.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Jan 31st, 2013 4:00PM