Avoid avalanche terrain and exposure to overhead avalanche terrain.
Heavy rain and high freezing levels will continue to create very dangerous conditions.
Cornices are large and looming. Strong winds and warming temperatures may increase the sensitivity. Cornices may trigger wet slabs or may step down to the persistent slab, creating larger than expected avalanches.
Two layers of concern exist within the upper snowpack: a crust layer is 60 to 80 cm deep and a weak layer of surface hoar/facet is 100 to 200 cm deep. These will likely become active with elevated freezing levels and heavy rain expected.
Rising freezing levels and rain will continue to weaken the surface snow. Large avalanches are very likely in steep terrain. Wet slabs are more likely at upper elevations, while wet loose will be more likely at lower elevations.
A natural avalanche cycle with numerous and large slabs (up to size 3) was reported in Fernie on Wednesday. They all occurred on alpine north to east-facing slopes.
On Tuesday, several natural avalanches (up to size 2) were obseved, including storm slabs and persistent slabs.
Looking ahead, natural avalanches are expected at all elevations due to continuous rain and elevated freezing levels.
High freezing levels and heavy rain are continuing to saturate the top 30 to 50 cm of surface snow to mountain tops. Cornices are large and looming and will likely weaken with the ongoing wet and warm storm.
Below this, a thick crust is found on all aspects and is buried down 50 cm. The thickness of the crust (from 1 to 10 cm) depends on elevation. Several recent avalanches have released on this layer.
Multiple buried weak layers of surface hoar and/or crusts still exist in the top 120 cm of the snowpack and will likely become active with the additional load from heavy rain.
The mid and lower snowpack is well settled and strong in most areas.
Wednesday Night
Cloudy. 5 to 10 mm of rain at treeline. 70 km/h southwest ridgetop wind. Treeline temperature 1 °C. Freezing level 2500 m.
Thursday
Cloudy. 5 to 10 mm of rain at treeline. 60 km/h southwest ridgetop wind. Treeline temperature 2 °C. Freezing level 2400 m.
Friday
Cloudy. 25 to 40 mm of rain at treeline. 60 km/h southwest ridgetop wind. Treeline temperature 4 °C. Freezing level 2700 m.
Saturday
Cloudy. 5 to 10 mm of rain at treeline. 40 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 2000 m.
More details can be found in the Mountain Weather Forecast.
