Watch for pockets of wind slab in cross loaded alpine terrain and immediately lee of ridge crest.
Confidence
Moderate - Timing of incoming weather systems is uncertain
Weather Forecast
We're looking at more mainly benign weather through the forecast period. Skies will be overcast and there may be periods of isolated flurries although accumulations are not expected to be significant. Winds will be mainly light from the southwest. There is poor agreement in the models about how high the freezing level with get with the high resolution regional model calling for it to rise as high as 1000m on Tuesday while the global calls for it to stay at valley bottom.
Avalanche Summary
No new avalanches were reported over the weekend but sluffing is expected to have occurred on steep south facing slopes. On Friday control work produced loose dry avalanches to size 1 on E and NE aspects. On Wednesday control work produced a size 2 storm slab on a high elevation east facing feature.
Snowpack Summary
The recent temperature inversion has helped the upper snow pack to settle a bit, at least at upper elevations. In sheltered areas around 40 cm of decomposing storm snow rests on 10 cm of facets. This interface has been producing moderate to hard shears in recent snowpack tests. In wind exposed terrain you're likely to find pencil hard wind slabs sitting on the facets. Our field team was out traveling around the region last week and they found surprisingly little wind effected snow. It sounds like the story is a little different around Castle Mountain where upper elevation terrain has seen quite a bit of recent wind out of the west and now north.
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.