Avalanche Forecast

Issued: Jan 19th, 2013 4:00PM

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.

Ski quality has gone downhill due to the winds and warm temperatures. Ice climbers avoid pockets of hard windslabs on steep features in the alpine. SH

Summary

Weather Forecast

Light to mod. NW winds Sunday (Front ranges may have E winds Sunday AM) . A trace of snow is possible over the front ranges, but overall dry conditions are in the forecast . Alpine temps around -10C Sunday with freezing levels near valley bottom.

Snowpack Summary

10-20+ cm variable windslabs from strong W/NW winds over last 3 days. 25-35cm over Jan 6 interface of facets and/or surface hoar (preserved W of divide treeline and below). Helen Ridge profile at treeline found mod. compression results on a 15cm surface windslab, with no results below on a mainly facetted snowpack. Thin sun crust on steep S slopes.

Avalanche Summary

No new avalanches reported today. Winward slopes have been scoured to the bare rocks in many areas East of the divide.

Confidence

on Sunday

Problems

Wind Slabs

Wind slabs to pencil stiffness are possible to trigger in steeper terrain. These are becoming more stubborn to initiate as warm temperatures bond these to the surfaces below. Caution where these sit over facets in thin snowpack areas.

Be careful with wind loaded pockets while approaching and climbing ice routes.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

The Jan 6 layer could be a failure plane in areas with enough load or on steeper steeper unsupported features. Dig down and look for surface hoar or prominent facets. (best preserved in the Kootenay region).

Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 20th, 2013 4:00PM