Regions
Banff Yoho Kootenay.
Another beautiful day forecasted for Wednesday! Watch for an increase in loose dry avalanche activity on solar aspects with daytime warming.
Weather Forecast
Another beautiful day for Wednesday with clear skies and day time highs of -5. Cloud will roll in Wednesday evening and very light flurries are forecasted for Thursday and Friday. We may see 5-10 cm by Friday evening in some locations.
Snowpack Summary
Prolonged cold temperatures have weakened the upper snowpack. Wind effect is common in the alpine and several recent crusts can be found on steep solar slopes. Despite the weakening slab above it, Jan 17 surface hoar lingers down 40-60 cm in isolated locations and produces hard, resistent shears. A weak basal snowpack exists in thin snowpack areas.
Avalanche Summary
The loose dry problem remains the main concern. We continue to see natural and human triggered avalanches out of most steep terrain. These avalanches are running far and entraining a substantial amount of snow. For example, Mt St. Piran had a size 2 loose dry avalanche which initiated in the rocks and ran 500 m, SE aspect, 2550 m on Monday.
Confidence
Due to the number and quality of field observations
Problems
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.