Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Little Yoho, Sunshine, West Side 93N.
As of Tuesday, wind slabs were minimal, even in the alpine. The key question for Wednesday is which wind forecast will materialize. Lower wind speeds will result in fewer wind slabs, while higher winds will lead to more. Pay close attention to local conditions and monitor carefully.
Confidence
Moderate
Avalanche Summary
The Sunshine Patrol reported another size 2 deep slab triggered by explosives in Delirium Dive. Similarly, Lake Louise Patrol triggered a size 1.5 deep slab in ER 5. See accompanying photo for details.
Snowpack Summary
10-20 cm of recent storm snow lies on an early-season snowpack measuring 50-90 cm at treeline. Two weak layers are present: the November 9 crust, found 25-40 cm above the ground, and an October crust near the ground, where facets and depth hoar are developing. Observations of the October layer are limited, but it appears most prominent on northerly aspects at treeline and above.
Weather Summary
Temperatures are expected to remain seasonal, with valley highs around -5°C and ridge temperatures near -12°C tomorrow. While some models hint at a few centimeters of snow on Wednesday, significant accumulation is unlikely. The primary concern is the wind, which could reach over 40 km/h from the west, though some models indicate lower speeds.
Terrain and Travel Advice
- Be aware of the possibility for full depth avalanches due to deeply buried weak layers.
- Pay attention to the wind; once it starts to blow, sensitive wind slabs are likely to form.
Avalanche Problems
Deep Persistent Slabs
The Oct 23 crust/facet layer just above the ground, is capped by a 50-80 cm slab and has been reactive all week, on NW through NE aspects in 30-45 degree alpine terrain. The extent of the problem remains uncertain, but we advise exercising extra caution on steep, open alpine features.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2.5