Avalanche Forecast
Issued: Dec 9th, 2019 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
Adam Greenberg,
Parks Canada
Increasing winds will continue to build slabs in the alpine and treeline. Approach wind affected terrain with care.
Summary
Weather Forecast
Tuesday: Cloudy with isolated flurries and an inversion with alpine highs of -2. Moderate to strong west winds.
Wednesday: Cloudy with isolated flurries with inversion breaking down and an alpine high of -7. Moderate west winds reaching strong to extreme overnight.
Thursday: Cloudy with flurries, alpine high of -5. and strong west winds.
Snowpack Summary
15-25cm storm snow coupled with moderate west winds has formed new slabs in the alpine. This overlies previous windslabs and a crust below 1800m. A melt freeze crust facet combo formed at the start of the season sits at the bottom of the snowpack. Though unlikely to be triggered by people, we have seen other avalanches stepping down to this layer.
Avalanche Summary
Saturday night's snowfall brought enough snow and wind to trigger a limited avalanche cycle in lee alpine terrain along the Akamina Parkway. In two cases these stepped down to early season weak layers on east aspects in the alpine. No new avalanches observed in the less snowy front ranges.
Confidence
Due to the number and quality of field observations
Problems
Wind Slabs
Increasing westerly winds will continue to build slabs in lee areas at treeline and in the alpine.
- Be cautious as you transition into wind affected terrain.
- Be careful with wind loaded pockets. Be aware of wide variation in snowpack depth
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A combination of melt freeze crusts and facets from early season snowfalls is lurking at the bottom of the snowpack. These layers are unlikely to be triggered by people but smaller avalanches in the recent storm snow have been stepping down.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
- Avoid thin rocky or unsupported terrain features.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 12th, 2019 4:00PM
