Avalanche Forecast

Issued: Feb 3rd, 2015 4:16PM

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

ian jackson, Parks Canada

Banff Yoho Kootenay.

The new snow has made for excellent ski conditions. A storm is approaching on Thursday that will raise the hazard if it materializes as forecast.

Summary

Weather Forecast

Light north winds and cold temperatures overnight (-20's). Wednesday looks like a nice day with alpine winds increasing to moderate from the west. The next system will be coming in mid-day on Thursday and we should see 30-50 cm with rising freezing levels to 1800m and increased winds from the SW.

Snowpack Summary

20-25 cm low density snow now sits on the Jan 30th crust. SW winds picked up overnight and created windslabs at higher elevations and in typically wind exposed areas. These are mostly small and confined to immediate lees. The very weak base of depth hoar continues to dominate the region, with moderate compression tests 25 cm above the ground.

Avalanche Summary

A large natural occurred on Mt. Stephen sometime in the last 24 hours. This was likely due to localized wind loading in the area overnight. There is a lot of low density snow available for transport so conditions can change quickly if wind is present.

Confidence

Intensity of incoming weather systems is uncertain on Thursday

Problems

Wind Slabs

In wind exposed areas and at higher elevations, moderate W winds have created soft slabs. These are primarily isolated to immediate lees at this time. In more sheltered areas, this may not be a problem - watch for wind effect on the surface!

Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

The base of the snowpack remains weak due to basal depth hoar/facets. Continue to avoid large open slopes with shallow snow and rocks, as this is the kind of place where this deep weakness could be triggered.

Avoid thin, rocky or sparsely-treed slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Feb 4th, 2015 4:00PM