New snow is sitting on a layer of surface hoar resulting in small, widespread, and reactive storm slabs.
Confidence
Low - Intensity of incoming weather systems is uncertain
Weather Forecast
Moderate to heavy snowfall is expected to continue overnight Tuesday with intermittent flurries or light snow forecast for Wednesday. There is quite a bit of variation in the forecast forecast but I expect between 10 and 25cm of new snow will have fallen by the end of the storm. Winds will be strong from the southwest becoming light through the day. The freezing level is expected to hover around 1500m. Thursday and Friday will be mainly cloudy with sunny periods and no significant precipitation expected. Winds will be mainly light from the southwest. The freezing level will be between 1500m and 1000m.
Avalanche Summary
No new avalanche have been reported as of publishing Tuesday evening.
Snowpack Summary
Up to 10cm of new snow overlies a crust on steep solar aspects, or a layer of surface hoar on sheltered and shady slopes at all elevations. Moderate to strong southwest through south east winds have been loading lee features. 10 to 15 cm below this is a second buried weak layer again consisting of a melt-freeze crust on solar aspects in the alpine or well-developed surface hoar in sheltered areas at treeline and lower elevations. Deeper still, the mid and lower snowpack is generally strong, with the exception of shallow snowpack areas that may be more faceted.
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.