You guessed it, snowfall and then extreme winds, and then snowfall. Watch for Wind Slabs low on the slope. The possibility also still exists to trigger persistent weaknesses in the mid to lower snowpack.
Weather Forecast
Wednesday: Strong Westerly wind, flurries, treeline highs of -12.Thursday: Strong West wind trending to Extreme, light snowfall possible in the afternoon, treeline highs of -7.Friday: Mix of sun and cloud, decreasing wind, treeline highs of -10.
Snowpack Summary
New snowfall is burying a variable snowpack with several layers of wind slab (from extreme West winds) at all elevations. In deeper snowpack areas, hard persistent slabs (from earlier SW winds) sit on a faceted mid and lower snowpack. In thin snowpack areas, several layers of hard wind slab are sitting on weak, large, developing depth hoar.
Avalanche Summary
Explosive control work at neighboring avalanche operations has been producing large avalanches in wind exposed terrain, especially in areas that were shallow prior to recent wind loading from the west.Shooting cracks and whoomphing were observed in pockets of hard wind slab over depth hoar in Eastern (shallow snowpack) areas.
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
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.