Storm snow has added load to a complex upper snowpack creating touchy avalanche conditions.
Stick to lower angle terrain with no overhead hazard.
A weak layer of surface hoar/crust/facets exists in the upper snowpack. Triggering this layer is possible but it's distribution is spotty. The most likely areas are on north facing terrain and was most recently reactive in the Flathead.
Recent storm snow will likely remain reactive as it settles. Cold temperatures may prolong its reactivity specifically where it has formed over a crust.
There was an avalanche fatality in the Matheson Creek area on Tuesday. See this MIN report for more details.
A cycle of natural, human, and explosive triggered storm slab avalanches up to size 2 occurred on Tuesday and Wednesday in the Lizard Range. In the Flathead and St Mary's ranges there have been reports of several remotely triggered (from a distance of 100+ m) storm and persistent slab avalanches up to size 3. Some have had very wide propagations and were 50-60 cm deep.
Roughly 50 cm of storm snow has developed touchy storm slabs over an upper snowpack that is variable and contains two distinct layers:
At 50 cm depth, a supportive crust exists on south-facing terrain. On north-facing terrain, this crust is breakable or absent.
Between 60 and 100 cm depth, a persistent weak layer of crust/facets with spotty surface hoar is present.
The persistent weak layer is becoming less reactive but continues to produce sporadic avalanches, particularly on north aspects where a supportive crust is absent and in less-travelled areas like the Flathead. Recent storm snow has increased the load on these layers.
Thursday Night
Mostly cloudy. 1 to 5 cm of snow. 20-30 km/h southwest ridgetop wind. Treeline temperature -12 °C.
Friday
Mostly sunny. 15-30 km/h west ridgetop wind. Treeline temperature -10 °C.
Saturday
Mostly sunny. 10-20 km/h southwest ridgetop wind. Treeline temperature -9 °C.
Sunday
Mostly sunny. 20-30 km/h south ridgetop wind. Treeline temperature -6 °C.
More details can be found in the Mountain Weather Forecast.
