Avalanche Forecast
Issued: Feb 12th, 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.
Grant Statham,
Parks Canada
Another 48-hour break between wind storms gives a nice few days. We continue to be concerned about isolated, large avalanches releasing on the deep facet layer. For this reason we recommend avoiding travel directly through avalanche start zones.
Summary
Weather Forecast
A ridge of high pressure will keep the weather over our region mostly fine for Thursday with just a trace of snow here and there and temps ranging from -7 to -12. The wind comes up again on Thursday afternoon/evening, forecast to reach 100 km/hr. 5 cm per day expected for Friday and Saturday.
Snowpack Summary
5-10 cm of dry snow over the past 24-hours brings the 7-day storm total to 25-40 cm across the region. Light winds today kept the surface soft, but strong winds on Tues may have left some lingering wind slab in high alpine areas. We remain very concerned about the facetted weakness deep in the snowpack and continue to urge avoidance of start zones.
Avalanche Summary
We were surprised by the lack of wind slab activity reported on Wednesday, considering the extreme winds on Tuesday - however we have no observations from the high alpine. The ski area teams today reported numerous size 1 loose dry sluffs running quite far, as well as one 24-hr old size 2 deep slab on Fatigue Mountain near Sunshine.
Confidence
Problems
Wind Slabs
We expect these in the very high alpine (~3000 m) and they could be buried under new snow. Unlikely to release naturally unless triggered by sun or more wind, but human triggering is possible if you find one. Feel for density changes underfoot.
- Use caution in lee areas. Recent wind loading has created wind slabs.
Aspects: North, North East, East, South East, South.
Elevations: Alpine.
Likelihood
Expected Size
Deep Persistent Slabs
We continue to see one of these avalanches every few days. Very isolated but very destructive. Avoid travel directly through avalanche starting zones until this layer has had more time to stabilize. That is the only answer: time and patience.
- 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 13th, 2020 4:00PM
