Uncertainty exists with forecast freezing levels and the bond within and below the recent storm snow, especially across different elevation bands. Be alert to conditions that change with elevation and make observations continuously as you travel.
Confidence
Poor - Due to variable snowpack conditions
Weather Forecast
Synopsis: The pattern calms down a bit as the flow becomes more zonal (westerly). A few weak features impact the coast through the weekend.Saturday: Freezing Level: 1200m Precip: 3-6mm/4-12cm Wind: SW Moderate gusting Strong.Sunday: Freezing Level: Surface Precip: Trace Wind: NW, Moderate.Monday: Freezing Level: 1200m Precip: Trace Wind: SW, Moderate
Avalanche Summary
Numerous size 2.5 - 3.0 avalanches are being reported from the Coquihalla where there hasn't been an overnight refreeze in days.
Snowpack Summary
The storm has delivered around 60 cm of heavy snow at upper elevations while simultaneously raining as high as 1900m as freezing levels fluctuated during the storm. Below 1500m the snowpack was reported to be isothermal as of Friday afternoon. The new snow has been settling rapidly and is slowly bonding to the previous snow surface, which includes faceted snow, surface hoar, and/or a crust. This interface is most concerning where the surface hoar is sitting on a crust on previously sun-exposed slopes. Cool temperatures should slow natural avalanche activity in the coming days but I suspect the snowpack could still use a bit of time to adjust to it's new load. We also need to gather more information on this interface before we think getting into the bigger terrain. The mid-pack is strong and well settled, although the entire snowpack will remain volatile below 1500m until it has a chance to freeze.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.