The storm has ended and temperatures are slowly cooling. The sun is expected to shine, the incoming solar radiation could be strong enough to trigger storm instabilities or cornices.
Weather Forecast
A high pressure ridge will keep the interior dry, cool and mostly clear for the next few days. Small disturbances will pass through the region but accumulation will be minimal. Winds are forecast to be light from the south.
Snowpack Summary
Cooler temperatures have tightened up the snowpack near the surface forming a crust with moist snow underneath it to ~2100m. Above 2000m is up to ~25cm of recent storm storm snow. Snowpack tests yesterday produced resistant planar results within the top 50cm. The Nov persistent weak layers are down ~100 and ~120cm.
Avalanche Summary
Avalanche control within the highway corridor west of the Rogers Pass summit yesterday produced mainly avalanches size 2.5 and up to size 3.0 showing wide propagation on the Nov 9 layer. Could not see all the results due to limited visibility. A backcountry natural avalanche cycle from a 2-3days ago from rain and warm temperatures is expected.
Confidence
Due to the quality of field observations
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
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.