Avalanche Forecast

Issued: Dec 25th, 2016 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Light temperature inversion in the valley making the alpine very pleasant. Enjoy the clear weather. Happy Holidays!

Summary

Weather Forecast

Clear sky's will prevail till tomorrow afternoon when a small system is expected to push in bringing light precipe with accumulations up to 15 cm.

Snowpack Summary

10-40 cm sits over the very weak Dec.19th facets. Wind slabs up to 60cm have been observed over this same layer in alpine areas. The new snow / facet interface proven touchy with avalanche control work over the last 5 days and will persist for some time. The Nov crust is 30-80cm deep and a few isolated observations indicate it to be reactive.

Avalanche Summary

Explosive control this week resulted in avalanches up to size 2.5-3. The largest involved windslabs that failed on the persistent Dec.19th facets. Notably, ski hills triggered a couple of size 2's with bombs that initiated on the Nov 12 crust on solar aspects where both a thin snowpack and pronounced crust exist. Limited natural activity seen

Confidence

Problems

Persistent Slabs

New snow and strong winds have created wind-slabs on exposed slopes that can be easily triggered. These slabs sit over a very faceted snowpack creating a weak interface that will last for some time.

Use caution in lee areas. Recent wind loading have created wind slabs.Be careful with wind loaded pockets while approaching and climbing ice routes.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Loose Dry

New snow amounts have slowly piled up, especially in Eastern areas with the influence of an up-slope flow. The weak Dec 19 facets do not provide much support for this snow and once a sluff is initiated in steep terrain, it can run a long distance

Be very cautious with gully features.Good group management is essential to manage current conditions safely.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Dec 26th, 2016 4:00PM