Silver Valley & Bitterroot Mountains

Warmer temperatures and light rain will slowly creep up the mountain and wet the recent snow, which may create the possibility for wet snow sluffs on steep slopes. Although these avalanches will be small, they could run longer distances in complex terrain or gullies where the surface crust is firm and creating a slick sliding plane. Avoid travelling in runout zones and crossing below large cliff bands if you see small sluffs gaining in size as it moves downhill or pinwheels naturally releasing.  

Incremental amounts of snow, rain and wind have led to a variety of avalanche problems, with different areas across the forecast region experiencing varying precipitation types and amounts. Areas within the Selkirk and Cabinet Mountains have received a modest 5 inches of snow since the shift in weather started, while the Silver Valley-Bitterroots measure closer to 3 inches.

Another weak disturbance passes across the Panhandle today, delivering another shot of precipitation. Unfortunately, warm temperatures are already in place, so the snow line will creep up to 5500’ in the north and 6000’ in the south. Below the rising snow line, light rain will fall in the valleys and slowly work up the mountains. As liquid input from increasing temperatures and rain affects the snow surface, small Wet Loose avalanches could materialize. Although these avalanches will be small in size, they may run longer distances than you might expect due to the firm surface and slick sliding plane below the new snow.

Above the snow line, several observations across the area have reported finding the surface hoar that developed during the long dry January spell to be preserved by the new snowfall in some locations. (Observation from the Silver Valley-Bitterroots) (Observation from the West Cabinets).One silver lining to the increasing temperatures and liquid moisture is that it may continue to help destroy some of those weak feathers at lower elevations. However, terrain above that and places that have seen lighter density snow and slightly colder temperatures- such as the northern Selkirks, have a better chance for these pesky weak layers to survive on more slopes for a longer time. What happens with the weather in the coming days will give us a better idea of the distribution.

With more snow available for transport in the Selkirk and West Cabinet Mountains, winds from the southwest will work to form new drifts below ridgelines and in the tops of steep gullies. Slopes that have drifts that are greater than about 6 inches will likely be more reactive and break wider across the slope if they have formed on a firm or icy surface. You can identify these new slabs by looking for shooting cracks in the new snow or seeing dune shaped pillows.  

Make sure to keep your avalanche brain engaged and continue to use good travel habits. If you get out and about, please consider dropping us an observation HERE or through the AvyApp. Something as simple as describing the weather and surface conditions goes a long way to help our forecast products and your local avalanche community. We have received some very helpful public observations recently, and we look forward to more.

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