Avalanche Forecast
Regions: Banff Yoho Kootenay.
Be alert in areas that harbor wind slabs. More snow and wind input is expected over the next two days.
Weather Forecast
Incoming snow will start on Thurs and deliver approximately 20cm to the forecast region by midday on Friday. The temperature will drop bringing sub zero values to the valley level again. The wind will increase and stay elevated throughout Thurs and Fri in the strong range from the SW.
Snowpack Summary
40-60 cm of settled snow overlies the Nov 5th crust with the higher amounts around Sunshine. Windslabs exist in alpine and at treeline. The crust is 1-10 cm thick and generally thickest around Sunshine. It extends up to 2400m on polar aspects and slightly higher around Sunshine and on solar aspects. Total snow depths at treeline are 50-100 cm.
Avalanche Summary
Avalanche control on 93S today produced a few slides up to size 2. Evidence of a previous natural cycle (last 36 hours) was evident up to size 2. Sunshine and Lake Louise ski patrol were able to trigger small windslabs with explosives today and most notably a Sunshine ski patroller ski cut a size 2 wind slab.
Confidence
Due to the number of field observations on Wednesday
Avalanche Problems
Wind Slabs
Wind slabs exist in the alpine and at treeline and more forecasted wind and snow will create new ones on Thursday. Today wind-slabs were triggered with explosives and ran on the Nov 5 crust, approx 50cm down.
- Use caution in lee areas. Recent wind loading have created wind slabs.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2
Loose Dry
With up to 20 cm forecasted Thurs/Fri, watch for sluffing in steep terrain. This will be less of a problem in areas that don't receive as much snow.
- Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.
- Use caution above cliffs where small avalanches may have severe consequences.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1.5