We're into a period of HIGH danger with ongoing loading of the snowpack on Wednesday into Thursday: rain to treeline and heavy snow in the alpine.
Confidence
Moderate - Intensity of incoming weather systems is uncertain
Weather Forecast
Warm and wet still on Thursday. Cooling with isolated flurries on Friday, and improving for Saturday.THURSDAY: Rain or wet snow (25-40 mm / cm) / Strong southerly winds in the afternoon / Freezing level around 1400 m. FRIDAY: Mostly cloudy with locally heavy flurries possible (5-15cm) / High temperatures to -1 Celsius / Light westerly winds / Freezing level around 1100 m. SATURDAY: Cloudy with sunny periods / Ridge winds light southerly / Freezing level around 900m / High temperatures to -2 Celsius.
Avalanche Summary
Several small loose wet avalanches were reported at treeline and below on Wednesday. Several natural storm slab avalanches to Size 2 were reported in the alpine on Wednesday.
Snowpack Summary
We had strong southerly winds and heavy rain to 1500m on Tuesday night (and rain to 2000m during the day Wednesday). This new rain (or snow higher up) sits on either wind slabs in the alpine or temperature crusts at treeline and below, especially on east and south aspects. Both of these surfaces will be good sliding layers for future snowfall. The mid and lower snowpack is generally well settled (strong). However, there remain a number of facet and crust layers (down 60-80cm in shallower areas) that are currently dormant but will require monitoring with additional loading (and warming this week), especially in the shallow, rocky areas.
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.