Wind slabs will continue to build in steep exposed terrain and deeper buried weak layers are demanding careful terrain selection right now.
Recent southerly wind formed wind slabs in lee terrain. Keep in mind that a wind slab release could also act as a trigger for the deeply buried late-December weak layer.
Triggering persistent slab avalanches remains possible due to several weak layers in the top metre of the snowpack. Facet layers are the primary concern in alpine terrain, while preserved surface hoar layers are the concern in treeline terrain.
On Wednesday there was a report of a size to cornice triggered persistent slab avalanche running in steep alpine terrain in the southeast portion of the region. There was also a report of a size 2 persistent slab avalanche on a west aspect at 1700 m on Tuesday.
Recent moderate southerly wind has formed wind slabs in lee terrain features near ridges.
Several persistent weak layers may be found in the top meter of the snowpack. These include a surface hoar layer buried on Dec 28 found 40 to 60 cm deep and a facet layer buried on Dec 23 found 60 to 100 cm deep. In alpine terrain, triggering one of these layers is most likely on steep rocky slopes where they present as facets. In treeline terrain, the layers are most likely triggered on steep slopes in open trees where they present as preserved surface hoar.
Friday Night
Mainly cloudy with scattered flurries. Light to moderate south wind. Treeline high temperatures around -6.
Saturday
Mainly cloudy with flurries, accumulation 3-5cm. Moderate southwest winds. Treeline high temperatures around -6.
Sunday
Cloudy with flurries, accumulation 5-8cm. Light south wind. Treeline high temperatures around -5.
Monday
Mainly cloudy with sunny periods. Light southwest wind. Treeline high temperatures around -6.
More details can be found in the Mountain Weather Forecast.
