Avalanche Forecast
Issued: Jan 22nd, 2017 5:34PM
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.
tim haggarty,
Avalanche Canada
Caution is still advised TL and below where a weak basal snowpack remains a concern. Watch for windslabs in the alpine. Parks Canada will be conducting Avalanche Control on Mts Bosworth, Field, Stephen and Dennis Monday Jan 23. No skiing or climbing!
Summary
Weather Forecast
A bit more cloud with a chance of trace amounts of precip for Monday before skies clear. Cold nights will be the price to pay for sunny afternoons with maybe some light winds reaching -5 C at valley bottom elevations. Watch for the sun to create moist snow on steep SW slopes given these conditions.
Snowpack Summary
Wind slab from SW winds in the alpine where mid-pack facets produce variable moderate to very hard shears down 100cm in deeper snowpack. Isolated SH produces easy shears below storm snow at treeline. Mid-pack facets produce consistent moderate results at Treeline and Below. Solar effects on Steep SW at treeline and more modest angles S-W BTL.
Avalanche Summary
A few deep persistent slabs were observed today both appeared fresh but could be up to 3 days old and were sz 2. SW aspect from 2650m on Mt Ogden failed about 60 deep and 60 wide running about 450m. On the NW aspect of Wapta above Emerald lake 80 deep and 80 wide running several hundred meters. Otherwise evidence of previous loose wet activity BTL.
Confidence
Problems
Wind Slabs
Moderate to strong SW winds with the storm that ended Dec 19 created wind slabs in specific alpine locations.
- Avoid steep lee and cross-loaded slopes
Aspects: North, North East, East, South East, South, South West, West.
Elevations: Alpine.
Likelihood
Expected Size
Storm Slabs
40cm of new snow has settled into slabs with the warm and humid weather. These continue to be reactive to tests around treeline where isolated SH has been found.
- Use conservative route selection, choose moderate angled and supported terrain with low consequence.
- Dig down to find and test weak layers before committing to a line.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Deep Persistent Slabs
While this layer still exists in the alpine and should be considered in shallow areas it is mainly TL and below where this sugary snow in the lower snowpack continues to produce moderate shears. Take extra care BTL where this layer is shallow
- Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.
- Choose the deepest and strongest snowpack areas on your run.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 23rd, 2017 4:00PM
