Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Little Yoho, Sunshine, West Side 93N.
The avalanche hazard is forecast to increase through Wednesday with continued elevated winds and snowfall.
Snowfall is forecast to be higher in the northern parts of the region.
Consider your exposure to overhead avalanche terrain carefully as a natural avalanche cycle can be expected.
Confidence
Moderate
Avalanche Summary
Over the weekend the Lake Louise avalanche control team reported working with small new windslabs. Sunday the Sunshine village avalanche control team controlled three cornices to size 2, one of which triggered a slab in the slope below.
Snowpack Summary
10 to 25 cm of snow over the past week has been redistributed by continuous moderate to strong west and southwest winds forming wind slabs overlying wind effect found 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-pack is weak in eastern parts of the region and more supportive in western areas along the divide.
Weather Summary
5cm of snow with strong west winds can be expected overnight Monday into Tuesday morning.
Tuesday another 5 cm is forecast with winds shifting SW and decreasing to moderate to strong. Alpine Temperatures remain steady at -5-10C.
Overnight into Wednesday up to 10cm of snow with winds shifting back to the west and decreasing into the moderate range as temperatures fall to -10C in the alpine.
Snow fall amounts for the period are expected to be lower south of the Kicking Horse Pass.
Terrain and Travel Advice
- Make conservative terrain choices and avoid overhead hazard.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Avalanche Problems
Wind Slabs
New snow and moderate to strong winds have formed wind slabs at alpine and treeline elevations. Strong winds and incoming snow will contribute to further slab formation though Wednesday. If triggered, there is potential for these 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 consists of weak facets and depth hoar with the upper snowpack forming a 40 to 110 cm thick slab above this weakness. Natural and human triggered avalanches on this layer remain a concern.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1.5 - 3