The recent storm snow may be most reactive to human triggers on solar aspects where the new snow is sitting on crust and/or in wind effected terrain.
Weather Forecast
THURSDAY NIGHT: Cloudy with isolated flurries; trace-5 cm. / Light to moderate, westerly winds / Alpine low -10 / Freezing level below valley bottom.FRIDAY: Mix of sun and cloud / Light to moderate, westerly winds / Alpine high 0 / Freezing level 1400 m.SATURDAY: Sunny / Light, westerly winds / Alpine high 1 / Freezing level 1600 m.SUNDAY: Sunny / Light, southerly winds / Alpine high 4 / Freezing level 2000 m.
Avalanche Summary
On Wednesday, several naturally triggered, size 1.5 storm slab avalanches and a few explosive triggered storm slabs up to size 2.5 were reported on primarily north aspects at treeline and above. On Tuesday, there were reports of several human triggered avalanches up to size 2. A few of these were triggered remotely (from a distance). There were also several reports of natural storm slab avalanches up to size 3. These avalanches occurred on all aspects and at all elevation bands.
Snowpack Summary
20-50 cm of recent storm snow sits mainly on facets (sugary snow), as well as surface hoar (feathery crystals) in sheltered areas and a crust on sun exposed slopes. At lower elevations, a weak layer buried in mid January can be found approximately 50-90 cm deep. This layer consists of surface hoar and facets, and may be combined with a crust on south facing slopes. This layer has been most reactive at treeline and below. Avalanche activity has dropped off significantly, however it may still be possible to trigger avalanches on this layer in areas such as steep cutblocks, and large open glades in the trees.The lower snowpack is generally considered to be strong, except for shallow, rocky areas where cold temperatures continue to facet (weaken) the snowpack.
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.