If the rain-soaked snow freezes as expected through Friday and Saturday, avalanche hazard will follow a decreasing trend until the next storm on Sunday. Please treat this forecast as an initial assessment, as we have little information at this time.
Confidence
Low - Due to the number of field observations
Weather Forecast
Friday: Mostly dry with freezing levels around 1500 m. Moderate southwesterly winds becoming light in the afternoon.Saturday: Dry. Freezing levels initially around 1500 m, but increasing later in the day. Light southwesterly winds, increasing in the afternoon.Sunday: 15-20 mm precipitation, starting as snow at treeline elevations, then turning to rain. Freezing level rising to around 2200 m. Strong southwesterly winds.
Avalanche Summary
Storm slab avalanches were observed early this week and I'm certain that avalanches would have been triggered by the onset of the rain. Whether avalanches are still running is a different question and unfortunately the weather and lack of observers is making that hard to determine. I'd expect a decrease in avalanche activity with cooling temperatures into Friday and Saturday.
Snowpack Summary
Rain and warm weather have resulted in a widespread wet upper snowpack. The freezing level rose to close to 3000 m on Wednesday and Thursday meaning very few places, if any, will have escaped the melt. The last 48 hours have seen the snowpack diminish by approximately 10 cm. Expect treeline snow depths of around 90 cm. A crust that formed around Halloween has been reported from neighboring regions and probably exists in the Lizard-Flathead region too around 50 cm below the surface.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.