Avalanche Forecast

Issued: Jan 15th, 2017 4:00PM

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

william lawson, Parks Canada

Banff Yoho Kootenay.

Forecasted snow accumulation values are uncertain with the incoming system. With the current snowpack structure, any significant load will dramatically change the avalanche hazard.

Summary

Weather Forecast

Warmer temperatures have arrived and are expected to continue over the week. Day time highs are expected to reach above freezing. A large low pressure system is moving across western Canada, bringing precipitation to the forecast region. Forecasted accumulation values have been varied.

Snowpack Summary

Hard wind slabs at treeline and above have formed over the past week from a Northern arctic air mass. These hard slabs are in many start zone areas overlying a weak, faceted snowpack. Loose snow on steep southerly aspects at lower elevations have cause loose snow avalanches entraining facets, warming temps and sun are the suspect trigger.

Avalanche Summary

Skier accidental size 1.5 off panorama meadows (Taylor Lake area) reported yesterday evening. Slab released on the deep persistent problem nobody was involved. Numerus loose dry avalanches were observed today from steep southerly aspects, snow appeared to be triggered from warming temps and solar output, entraining the faceted snowpack below.

Confidence

Problems

Deep Persistent Slabs

The lower half of the snowpack is garbage, and will be for the distant future. Facets, crusts and depth hoar make for a very unsupported base of the snowpack. These are also harder to initiate, but will cause a large avalanche if triggered.

Be aware of the potential for wide propagations.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Loose Dry

Loose dry avalanches observed out of steep solar aspects at lower elevations, this loose snow has the potential to entrain the very faceted snowpack and gain mass quickly. Main terrain concern is when traveling in gully features while ice climbing.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 16th, 2017 4:00PM