Human triggered avalanches may become more likely as warm temperatures allow the storm snow to settle into a more cohesive slab. Keep a close eye on steep sun exposed slopes throughout the day, warming may initiate natural loose avalanches.
Weather Forecast
A warm dry pattern is expected for the next few days. The upper ridge will shift eastward on New Year's Day, which should allow freezing levels on the Coast to rise to around 2500 m. This pattern is expected to stick with us for the foreseeable future. MONDAY: Temperature Inversion with below freezing air in the valley, above freezing (warmer) air between 1400 m and 2600 m, a few clouds, very light northwest wind, no snow expected.TUESDAY: Scattered cloud, freezing level rising to around 2600 m mid-morning, light southwest wind, no snow expected.WEDNESAY: Cloud cover increasing to overcast throughout the day, freezing level around 2700 m, light variable wind, no snow expected.
Avalanche Summary
On Saturday control work produced storm slabs, wind slabs and loose dry avalanches to size 2 with crowns 20 to 50 cm in depth. One isolated loose wet avalanche was reported on a solar aspect which could be a portent of things to come.
Snowpack Summary
Two successive storms produced 50 to 70 cm of storm snow with wind out the southwest, south and southeast that was strong at times. All of this new snow rests on a variety of old surfaces including crust on solar aspects, old wind slabs, facets and isolated surface hoar below treeline. Warming temperatures will likely allow the storm snow to settle into a more cohesive slab. 40 to 100 cm below the surface there is a widespread melt-freeze crust that was buried on December 15th. This layer has not produced much in the way of avalanche activity, but could come to life as the overlying slab becomes more cohesive as temperatures warm. Beneath the December 15th layer, the lower snowpack is generally strong and well settled.
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.