Regions
Northwest Coastal.
Confidence
Fair - Due to limited field observations
Weather Forecast
Another strong frontal system should reach the area by Monday morning bringing heavy snowfall and strong southwesterly winds. Expect another 25-40cm with this storm. The freezing level should be around 1000-1200m on Monday. Precipitation should taper off on Tuesday as a ridge of high pressure builds in. Mainly sunny skies are expected on Wednesday. The freezing level should be around 500-800m on Tuesday and Wednesday.
Avalanche Summary
Recent reports are limited to the run out zones along the highway corridors near Bear Pass and Terrace. I expect a widespread natural avalanche cycle occurred in many areas on Saturday and into Sunday.
Snowpack Summary
Saturdays system dumped another 50-75cm in many areas. The snowpack depth near treeline is already around 300cm. Fluctuating freezing levels and varying precipitation intensity and wind throughout the recent storms has probably resulted in various weaknesses within upper snowpack. A buried surface hoar layer may be found down close to 100cm, but there is no recent information on the presence and sensitivity of this layer. The mid and lower snowpack is generally well settled and strong with an old rain crust near the ground.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.
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.