Regions
Northwest Inland.
Don't let your guard down as you transition into wind-affected terrain.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
A mix of sun and cloud with light to moderate southerly winds and isolated light flurries is expected for Tuesday and Wednesday, before increasing cloud and wind with 2-5cm of snow for Thursday. Freeing levels should remain in valley bottoms for the forecast period.
Avalanche Summary
Reports from Sunday include generally small skier triggered storm and wind slabs avalanches, some of which ran on surface hoar buried a week and a half ago. Skier triggered sluffs were also reported to run far.
Snowpack Summary
The region has a mix of wind slabs and developing storm slabs. In higher snowpack areas in the northwest of the region, the storm slab has become reactive to human triggers. In most other areas the wind slabs are thin and stiff. Buried surface hoar is layered through the thin snowpack, and cool temperatures as well as limited loading have preserved these weak layers. The mid pack that was reported to be well settled may have now facetted in the shallower areas, and the deeper basal layers are almost certainly facetted and weak. We have not heard of any full depth releases on weak basal layers yet.
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.