Regions
Banff Yoho Kootenay.
Dangerous avalanche conditions still prevail. Use conservative route selection and avoid steep open terrain. No climbing or skiing on Mt. Stephen, Mt. Whymper, Mt Bosworth , Bourgeau or Eagles tomorrow as avalanche control is planned.
Weather Forecast
A ridge of high pressure in the wake of the cold front will bring mainly sunny skies for Monday. Another weak pacific storm is headed inland for Tuesday.
Snowpack Summary
60 cm of storm snow with both westerly and northerly winds has created a weak unstable storm slab instability on all aspects at and above treeline. Below treeline, the moist snow, facets and wet slab problem will disappear with cold temps.
Avalanche Summary
A widespread avalanche cycle has been occuring over the last 36 hrs. Avalanches to size three have run on all steep terrain and elevations. The slabs have been more likely to propagate at the treeline elevation.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Wet Slabs
Wet Slab avalanches are the release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slabs can be very unpredictable and destructive.