We have a very weak, faceted, basal layer in our snowpack at Rogers Pass.
Avoid thin, rocky, unsupported features where one could sink into the sugary facets, potentially triggering the deeper persistent weak layers.
30-60cm of settled storm snow buries the Dec 23 facet interface. This layer will be a concern in steep terrain, on convex rolls, or areas where the snowpack is unsupported (pillows, hanging snow fields, etc.).
The Nov 17 layer, down 60-120cm, consists of facets, a rotting crust, and decomposing surface hoar. This layer still shows hard, sudden collapse/planar results in snowpack tests. Though becoming less likely to trigger, the resulting avalanche would be quite large.
Several natural sz 2 slab and loose avalanches were observed in the highway corridor on Tuesday and Wednesday. Most were from steep, rocky S aspects, with the exception of a larger slab from Macdonald Gully 10.
On Monday a size 2 avalanche was remotely triggered from a shallow snowpack area on Bruins Ridge. These are the spooky avalanches that are causing anxiety amongst avalanche forecasters! Stay away from thin, rocky areas!
The top 30cm of snow is low-density and provides great powder turns. Steeper SW and W aspects have a thin sun crust on the surface. The Dec 23 facet interface, down ~70cm, is gaining strength. The Nov 17 facet/crust/surface hoar layer is still active in snowpack tests, exhibiting 'sudden collapse' or 'sudden planar' results.
Clouds, flurries, and slightly elevated freezing levels (FZL) will be the norm for the next few days. No major storms in the foreseeable future. Darn, eh!?
Thurs: mainly cloudy, trace snow, Alp high -2*C, 1600m FZL, light S winds
Fri: cloud with scattered flurries, 5cm, Alp high -4*C, 1500m FZL, light/gusty SW winds
Sat: flurries, 5cm, Alp high -4*C, 1600m FZL, light SW winds
