Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Little Yoho, Sunshine, West Side 93N.
Watch your exposure to overhead hazards, forecasted strong winds Monday will continue to transport snow at upper elevations.
The avalanche danger will increase by Tuesday, with 30cm of snow expected for the region.
Confidence
Moderate
Avalanche Summary
1 size 2 natural avalanche was reported from steep alpine terrain in the backcountry near the Sunshine ski hill. Local ski hills targeted cornices with explosives, producing avalanche results to size 2.
Snowpack Summary
10 cm of new snow over the weekend. Continuous moderate to strong west winds have formed new wind slabs which overlay extensive wind effect at alpine and treeline elevations. The upper snowpack has several crusts and weak interfaces from January down 15-50 cm. The Nov 16 deep persistent facet layer is down 40-110 cm and continues to produce sudden test results. The mid and lower pack is weak in eastern regions and more supportive in western areas and along the divide.
Weather Summary
A cold front will pass over the forecast region Sunday evening depositing 1-3cm of snow. Strong Westerly wind values are forecasted for Monday. Value temperatures will stay below freezing for the start of the week. By Tuesday another pulse of snow could deposit an additional 30cm of snow.
Terrain and Travel Advice
- Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
- In times of uncertainty conservative terrain choices are our best defense.
Avalanche Problems
Wind Slabs
New snow and moderate to strong winds have formed wind slabs at alpine and treeline elevations. Strong winds Monday will add to this new slab development. Natural and skier-triggered avalanches have been noted on this problem. If triggered, there is potential for these wind slabs to step down to deeper layers in the snowpack resulting in larger avalanches.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2
Deep Persistent Slabs
The lower snowpack is comprised of weak facets and depth hoar with the upper snowpack forming a 40 to 110 cm thick slab above the weakness. Natural and human triggering on this layer remains a concern.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1.5 - 3