New snow falling Monday into Monday night has promoted storm and wind slab development. The north part of the region may have received more snow than is indicated. If local amounts are higher than indicated the danger may be Considerable.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
MONDAY Night: Snow, accumulation 5-15 cm / moderate southwest wind / alpine temperature -8 CTUESDAY: A mix of sun and cloud with isolated flurries / light northwest wind / alpine temperature -5 C / freezing level 1200 m WEDNESDAY: Cloudy with sunny periods / light to moderate west wind / alpine temperature -8 C / freezing level 900 mTHURSDAY: Cloudy with sunny periods / light southwest wind / alpine temperature - 7 C / freezing level 1000 m
Avalanche Summary
Reports on Saturday and Sunday. include several natural and human triggered storm slab, loose dry and wind slab avalanches to size 1.5. On Sunday there was a skier triggered size 2 persistent slab avalanche on a west aspect at 2300m in the north part of the region as well as a remotely triggered (from a distance) size 3 avalanche on a southwest aspect in the alpine. The second avalanche was in the south part of the region. Both of these were suspected to have run on a layer of facets.There was also a report of a remotely triggered size 2 persistent slab avalanche on a north aspect at 2300m in the south of the region on Saturday. It was suspected to have run on a buried layer of facets.
Snowpack Summary
20-45 cm of recent storm snow is sitting 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. There are two weak layers of surface hoar in the upper snowpack that were buried in late January and early February. They can be found between 40-90 cm below the surface. These layers consist primarily of surface hoar, though they may be associated with crusts on steeper, south facing slopes. These weak layers are most prominent on south facing slopes and all aspects below treeline. Avalanche activity on these layers has declined in recent days, however it may still be possible to trigger an avalanche in isolated areas such as steep cutblocks, large open glades, and steep south facing terrain.The lower snowpack is generally considered to be strong, except for shallow, rocky areas where the 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.