Regions
Banff Yoho Kootenay.
We have increased the danger rating due to loose dry avalanches which can run further than expected in steep terrain, especially gullies where the sluff can collect and travel far. SH
Weather Forecast
Friday looks like a cold one with highs in the -20's. Some forecasts are calling for 15cm from Thursday to Sat with light to moderate winds shifting to the East. There is potential for temperatures to start moderating at the start of the New Year.
Snowpack Summary
The upper snow-pack is facetting with the cold temperatures and starting to sluff easily in steep terrain. Some thin, hard wind slabs observed in lee areas in the alpine. The Dec.15 layer of surface hoar (below 2100m) and hard surfaces or facets (depending on location) is down 15-30 cm. Some moderate shears have been observed around this interface.
Avalanche Summary
Avalanche control at Sunshine Village resulted in very thin wind slabs which were very stubborn in nature out of very steep terrain. The main concern was the facets which were initiated and acted as a loose dry avalanche running further than expected. Similar reports from recreational ski parties in steep gully terrain.
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.