Avalanche Forecast
Issued: Feb 26th, 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.
Stephen Holeczi,
Parks Canada
Watch locally for wind slab development Thursday. Also be curious about snowpack depths as thinner areas will likely have more pronounced basal facets. Great skiing in sheltered areas.
Summary
Weather Forecast
Alpine winds at 3000m will be in the 70kmh range Thursday with 5cm of snow possible. Temperatures at treeline will range from -10 to -4C. Expect 5cm Friday and 10cm on Saturday.
Snowpack Summary
10-20 cm of recent storm snow covers previously formed wind slabs in lee areas, and buried sun crusts on steep solar aspects. The Feb 1 rain crust is down 20-50 cm and present below 1900 m. In thin snow pack areas a dense mid-pack sits over a weak, faceted base. Thick snowpack areas have a denser base with few weaknesses.
Avalanche Summary
Local ski hills reported newly formed windslab isolated to immediate lee slopes off ridge crest. Ski patrol were able to produce size 1 avalanches on this layer with ski cuts. Some large sloughs out of extreme cliffed terrain.
Confidence
Wind speed and direction is uncertain on Thursday
Problems
Wind Slabs
Wind slabs are present in lee areas of the high alpine. So far these are small but have been reported as a touch more reactive than yesterday.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: Alpine.
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.
- Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.
- Use caution in thin snowpack areas.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 27th, 2020 4:00PM
