Avalanche Forecast

Issued: Feb 1st, 2014 4:01PM

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

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

Good skiing West of the divide in sheltered areas. Avoid thin areas in big alpine features as the basal layer can still be triggered. SH

Summary

Weather Forecast

Light N winds Sunday with a mix of sun and cloud and a trace of snow. Temperatures will again be in the minus 20's in the mornings, and highs in the -10 to -15C range.

Snowpack Summary

5-15cm of snow over the Jan 30th surface hoar/sun crust layer. Surface hoar most prominent at treeline and below. In Yoho today, thin wind slabs (15cm) over 5cm sun crust on steep S aspects reactive to skier triggering. The basal facets remain weak, but the overall snowpack is gaining strength. Glacial coverage very thin for this time of year.

Avalanche Summary

One size 2 natural cornice triggered avalanche on a SE aspect in Yoho occurred within the last 48 hours.Â This was a thin slab in extreme terrain.

Confidence

on Sunday

Problems

Deep Persistent Slabs

Thin snowpack areas in steep, alpine terrain will be the place to trigger the basal depth hoar/crust.

Be aware of thin areas that may propogate to deeper instabilites.Be aware of the potential for full depth avalanches due to deeply buried weak layers.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Storm Slabs

Places which have a well defined sun crust will be the most susceptible to triggering a storm slab. At the moment these are of lower consequence and thin (15-30cm) and isolated to specific terrain features.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 2nd, 2014 4:00PM