Regions
Northwest Inland.
Forecast snowfall amounts are uncertain. Pay close attention to how much snow falls in your area, and choose terrain accordingly.
Confidence
Fair - Intensity of incoming weather systems is uncertain on Thursday
Weather Forecast
A pacific storm will intensify on Wednesday night bringing snowfall to the region for Thursday and Friday. A clearing trend is forecast for Saturday. Up to 15cm of snow is forecast for Wednesday night and Thursday. Around 5cm of snow is expected on Friday. Only light flurries are forecast for Saturday. Ridgetop winds should remain strong to extreme from the southwest. Freezing levels are expected to hover between 1200m and 1500m with Friday being the warmest day.
Avalanche Summary
On Monday, a skier triggered a size 2 wind slab on a NE aspect at 1300 m. Several loose avalanches also failed on steep sunny slopes. Click on the blue dot on the map to see a recent wind slab that may have failed naturally or remotely in Sinclair. It was a thick, hard wind slab on a north aspect. There are likely to more like this lurking. New snow and wind on Thursday will likely promote further wind slab activity.
Snowpack Summary
Anywhere from 20 to 120 cm recent storm snow has been redistributed by winds into soft and hard wind slabs at alpine and treeline elevations (highest storm snow amounts were in the north and west). This overlies various surfaces including old wind slabs, hard crusts, surface hoar, and/or surface facets. New snow and wind on Thursday is forecast to form new wind slabs in exposed lee terrain.At the base of the snowpack, weak facets may be found. Cornices are large and potentially fragile. Below treeline, the snow appears to be in a spring melt-freeze cycle.
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.