Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible - Likely
- Size
- 1–2.5
This layer is concerning when there is a cohesive slab overlying the January Facets and Surface Hoar layer.
Freezing levels arn't dropping significantly until friday night. Be patient while the avalanche hazard remains elevated from the ongoing heat.
Recent warm weather and avalanche activity has created rugged and hazardous backcountry travel conditions.
This layer is concerning when there is a cohesive slab overlying the January Facets and Surface Hoar layer.
Rain and warm temperatures have saturated much of the snowpack at treeline and below treeline. This has resulted in widespread wet loose avalanches happening in steep terrain. The snowpack below treeline will remain weak and saturated until temperatures cool down friday night.
The base of the snowpack is inherently weak and untrustworthy. Human and natural triggering of these basal facets remains possible to likely.
Natural avalanche activity tapered yesterday with a few loose wet avalanches reported below treeline. Although natural avalanche activity is tapering, the snowpack will remain unstable until the temperatures really cool down friday night.
Previous widespread avalanche activity over the past week produced numerous natural avalanches at all elevations. This included some impressive avalanches up to size 3.5 at higher elevations, as well as loose wet up to size 2.
Previous Strong S and SW winds created wind slabs in the alpine areas where snow is still dry for transport.
Previous high freezing levels, rain, and solar radiation has formed a surface crust up to 2500m. Below 2100m 5-10cm of moist snow surface snow turns to a fully saturated snowpack around 1900m.
Persistent weak layers formed in early January are down 20-30cm in sheltered areas. Well developed facets and depth hoar make up the bottom of the snowpack.
The Mountain Weather Forecast is available at Avalanche Canada https://avalanche.ca/weather/forecast
Friday
Mainly cloudy. Alpine temperature: High -1 °C, with freezing level at 2100 metres. Ridge wind west: 10 km/h.
Saturday
Mainly cloudy with isolated flurries (trace). Alpine temperature: Low -10 °C, High -6 °C and freezing level at 1500 metres. Light ridge wind.