New snow falling Monday into Monday night has promoted storm and wind slab development.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
MONDAY Night: Flurries, accumulation 5-10 cm / moderate to strong southwest wind / alpine temperature -8 CTUESDAY: A mix of sun and cloud with isolated flurries / light to moderate west wind / alpine temperature -5 C / freezing level 1100 m WEDNESDAY: Cloudy with sunny periods / light to moderate west wind / alpine temperature -6 C / freezing level 900 mTHURSDAY: Cloudy with sunny periods / light southwest wind / alpine temperature -4 C / freezing level 1200 m
Avalanche Summary
Expect the likelihood of triggering storm and wind slab avalanches to increase as new snow has accumulated Monday into Tuesday.
Snowpack Summary
A couple of snowfalls over the past week have deposited 20-40 cm. This sits mainly on wind slabs and 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 50-60 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.