Watch for the shallow, weak areas in the snowpack. There is still significant variability in snow depths.
Weather Forecast
A cold, clear day in Rogers Pass today. Winds will remain light NW. Into the evening and tomorrow, a frontal system tracks across the region, bringing 10-15cm of snow by Friday night. SW winds will spike mid-day to strong, with freezing levels rising to 1000m.
Snowpack Summary
20-30cm of snow covers a supportive crust below 1600m. 20-80cm of settled snow covers the Dec 2 interface, which is surface hoar below tree-line and a sun crust on steep, solar tree-line and alpine features. The depth is variable due to wind-scouring. At shallow depths, it is still reactive in snowpack tests in the moderate to hard range.
Avalanche Summary
Sluffing and skier triggered size 1's from sidewalls of steep gully features have been reported in the alpine. Yesterday, a team was able to ski cut small size 1's from steep, unsupported features at and below tree-line in NRC Gully. These soft slabs were failing on the Dec 2 surface hoar/sun crust, which was only 20cm deep due to wind-scouring.
Confidence
Intensity of incoming weather systems is uncertain
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.