The snowpack is getting a nice refresh today, but the new snow will not bond well to the surface hoar and crusts that are being buried. Watch for signs of increasing avalanche hazard (like sluffs) as the new snow continues to accumulate.
Weather Forecast
A weak system will bring light precipitation with up to 5cm of accumulation today. Freezing levels rise to 1500m with an alpine temperature of -5.0 and southwest winds 20-40 km/h. A second stronger system arrives later tonight bringing another 15cm of snow by Saturday afternoon and strong southwest winds. High pressure builds up again for Sunday.
Snowpack Summary
10cm of new snow fell overnight with light southerly winds. The new snow conceals hard wind slabs in exposed alpine areas, a crust on steep solar aspects, and large surface hoar in sheltered areas. The Nov 21 persistent weak layer is down ~180cm.
Avalanche Summary
A natural size 2.0 avalanche was observed from steep north facing terrain adjacent to the the highway east of Rogers Pass.
Confidence
Intensity of incoming weather systems is uncertain
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.