Avalanche Forecast

Issued: Feb 2nd, 2012 4:00PM

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

Chris Gooliaff, Parks Canada

Banff Yoho Kootenay.

Strong solar radiation and warm p.m. temp's will cause instabilities on south aspects, as well as weaken cornices at ridge tops. Inversions (cold valley-bottoms and warm alpine bowls) are expected, so pay attention to how warm it feels as you ascend.

Summary

Weather Forecast

Snowpack Summary

Avalanche Summary

Confidence

The weather pattern is stable

Problems

Wind Slabs

Recent strong SW winds have created windslabs up to a metre thick on lee slopes in the alpine (primarily N- E aspects). Although these slabs are starting to settle out with warm temps, it is still possible for a skier to trigger these slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Cornices

The warm alpine temp's forecasted may be the straw that broke the cornice's back. If cornices do drop onto lee slopes, it could be a heavy enough trigger to step down into the basal facets. Several natural cornice avalanches were observed today.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 4

Persistent Slabs

In many areas east of the divide where the snow is shallower the mid-pack overrides a layer of weak basal facets. Be extra cautious of thin snowpack areas where the chance of triggering this layer is highest.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 4

Valid until: Feb 3rd, 2012 4:00PM