Avalanche Forecast
Issued: Feb 27th, 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
Great skiing continues in sheltered areas. Watch for new wind slabs in lee areas and stay curious about snowpack depths as thinner areas will likely have more pronounced basal facets and a weaker base.
Summary
Weather Forecast
Temperatures remain fairly warm on Friday with treeline staying around -5'C near the divide but getting warmer on the eastern slopes. Winds will remain in the moderate range out of the SW. We will see continued flurries with a couple cm's of new snow during the day and more intense flurries starting in the evening.
Snowpack Summary
Wind effect in the alpine due to gusty SW winds. New wind slabs in lee areas. 10-20 cm of recent snow over buried sun crust 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 wind slabs isolated to immediate lee slopes near ridge crests. Ski patrol and Visitor Safety teams were able to ski cut size 1 avalanches on this layer. Some large sluffs out of extreme rocky terrain up to size 1.5 were reported and one natural cornice failure was observed.
Confidence
Intensity of incoming weather systems is uncertain on Friday
Problems
Wind Slabs
Wind slabs are present in lee areas of the alpine with isolated wind slabs down into treeline in some areas. These are small and generally stubborn but are present in more areas due to increased winds on Thursday.
- 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 28th, 2020 4:00PM
