Avalanche Forecast
Issued: Feb 23rd, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
conrad janzen,
Parks Canada
Continue to avoid wind loaded areas in steep terrain, and make cautious route choices in areas with a thin snowpack where the basal weaknesses are more prominent.
Summary
Weather Forecast
Monday will be cloudy and see a few light flurries with 2-5 cm of new snow accumulation. Alpine temperatures remain cool with highs around -14'C. Light to moderate W and NW winds are expected through the day.
Snowpack Summary
5-15cm of snow in the last 48 hrs with moderate to strong alpine winds Saturday creating fresh wind slabs in lee areas. Isolated buried sun crusts exist on steep solar aspects. The Feb 1 crust is down 20-50cm and present below 1900m. In thin snow pack areas a dense mid-pack sits over a weak, faceted base. Thick snowpack areas have a denser base.
Avalanche Summary
A few natural and skier triggered wind slabs in the alpine up to size 2 have been reported and observed over the last several days. Some sluffing of the new snow in steep terrain has been observed in areas that got the most new snow over the last couple days.
Confidence
Due to the number and quality of field observations
Problems
Wind Slabs
Recent moderate to strong SW winds have formed wind slabs in lee areas of the alpine with isolated pockets of wind slab down into treeline. Cornices have grown very large in recent weeks, so watch your exposure to them carefully.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Avalanche activity on the basal facets has slowed down but the weakness in the snowpack remains a concern. These are hard to predict, but are most likely in areas with a thin snowpack (<150cm) where the basal facets and depth hoar are prominent.
- Use caution in thin snowpack areas.
- Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 24th, 2020 4:00PM
