At this point in the storm the serious problem exists where the precipitation is falling as snow.
Confidence
Fair - Freezing levels are uncertain
Weather Forecast
The forecast period features a sustained freezing level around 2000m, strong to extreme SW winds and significant precipitation. 25 to 40mm are expected Thursday night, 20 to 30mm Friday and another 15 to 20mm Saturday. Visit avalanche.ca/weather for a comprehensive look at this dynamic weather pattern.
Avalanche Summary
No significant avalanche activity to report form Wednesday. I suspect that there should be plenty to report from Thursday.
Snowpack Summary
The storm initially produced 5 - 15 cm of new snow before switching to rain mid morning. Temperatures had warmed to 0 C at 2200m by early afternoon. This snow/rain combo is likely saturating the 10 to 30cm of new snow that overlies a hard rain crust which exists up to at least 2100m. Strong west/southwest winds are likely shifting the remaining cold snow at upper elevations into wind slabs. Deeper snowpack weaknesses have become unreactive on account of the strong capping crust layer. We'll be watching the strength/temperature of this capping layer closely through the weekend.
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.