Avalanche Forecast
Issued: Jan 23rd, 2017 4:48PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Storm Slabs and Deep Persistent Slabs.
brian webster,
Avalanche Canada
Summary
Weather Forecast
Mixed sun and cloud with no snow forecast through the middle of the week. Winds will be light from the north on Tuesday with freezing levels near surface.
Snowpack Summary
Below 1900 metres the midpack is weak and facetted. Above this elevation the snowpack is more settled. In the alpine some windslabs persist from last weeks SW winds. Snowpack tests in Emerald Lake area found isolated areas of surface hoar below last weeks storm snow. Where found this surface hoar was producing easy shears.
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Avalanche Summary
Avalanche control in Yoho Park today (Bosworth, Stephen and Mt Dennis) produced numerous size 2 and 2.5 avalanches. One size 3 was triggered on Mt Bosworth. No fresh natural avalanches were observed.
Confidence
Problems
Wind Slabs
Lingering windslabs exist from last weeks stronger winds. Watch for these windslabs as you transition into alpine terrain.
- Avoid steep lee and cross-loaded slopes
Aspects: North, North East, East, South East, South.
Elevations: Alpine.
Likelihood
Expected Size
Storm Slabs
Last weeks storm snow has settled into a 20-40 cm slab. This slab is starting to settle out, but snowpit tests show this layer to be reactive in some locations, particularly around treeline where surface hoar has been found.
- Dig down to find and test weak layers before committing to a line.
- Use conservative route selection, choose moderate angled and supported terrain with low consequence.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
This layer is mainly a concern below treeline where the facetted snow in the lower snowpack continues to produce moderate shears.
- Choose the deepest and strongest snowpack areas on your run.
- Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 24th, 2017 4:00PM
