Storm snow will increase through the day. Coupled with moderate wind, storm slabs will be most reactive in lee terrain.
Cautious route-finding, and conservative decision making is key.
A weak layer of surface hoar/crust/facets exists in the upper snowpack. Triggering this layer is still possible but it's distribution is spotty. The most likely areas are on north facing terrain and was recently reactive in the Flathead.
Fresh storm slabs will likely be sensitive to human triggers especially at upper elevations where wind is redistributing new snow.
On Sunday, size 2 storm slab avalanches were artificially triggered in steep alpine terrain
On Saturday, Widespread storm slab avalanche activity was observed. Slabs were size 1.5 to 2, triggered naturally and artificially.
Going forward, we expect storm snow to remain reactive especially where it is being redistributed into lee terrain by moderate wind from the south.
Up to 10 cm of new snow will bring recent storm snow totals to roughly 40 cm. This new snow sits over a variety of surfaces including wind affected snow, surface hoar in sheltered areas and crust on solar aspects and low elevations.
Below this, depending on aspect and elevation, the upper snowpack may contain two more layers of crust, facets and/or surface hoar formed in late January and early February. We have uncertainty around the reactivity of these layers.
The mid and lower snowpack remain well settled, with no significant concerns at this time.
Sunday Night
Mostly cloudy. 1 to 2 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -6 °C.
Monday
Cloudy. 5 to 10 cm of snow. 40 km/h south ridgetop wind. Treeline temperature -3 °C. Freezing level 1500 m.
Tuesday
Mostly cloudy. 10 cm of snow. 20 km/h southwest ridgetop wind. Treeline temperature -5 °C.
Wednesday
Mix of sun and clouds. 1 cm of snow. 10 km/h south ridgetop wind. Treeline temperature -14 °C.
More details can be found in the Mountain Weather Forecast.
