With the sun potentially coming out for an extended period of time on Thursday, expect storm slabs to be reactive at upper elevations
Confidence
Moderate - Timing or intensity of solar radiation is uncertain on Thursday
Weather Forecast
THURSDAY: Cloudy with sunny periods / Light north wind / Alpine temperature -1 / Freezing level 1000mFRIDAY: Mainly cloudy / Light west wind / Alpine temperature -1 / Freezing level 1100mSATURDAY: Isolated flurries / Light west wind / Alpine temperature 2 / Freezing level 1400m
Avalanche Summary
On Thursday expect reactive storm and wind slab avalanches in the alpine and tree line elevation bands where the recent precipitation has fallen as snow. Below tree line expect small loose snow avalanches where rain has soaked the snowpack.
Snowpack Summary
The last 48 hours has seen very heavy amounts of precipitation. The freezing level hovered around tree line during that time. Reports from the region have been few and far between, however it can be expected that 70-100cm of snow has fallen at upper elevations. The new snow would have been redistributed by moderate to strong southwest wind and is sitting on a well settled lower snowpack. Rain below tree line has soaked an already moist and/or wet lower 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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.