Silver Valley & Bitterroot Mountains

Stiff, wind-drifted slabs now rest above weaker snow layers and crust on leeward-facing slopes. These will be more problematic and increase your avalanche risk where they sit above a hard, slippery sliding surface versus a moist old snow surface. Approach northerly and easterly-facing slopes with about 8 inches of new snow with extra caution, and make mindful terrain choices if traveling near slopes around 35 degrees.

The latest storm is slowly winding down. Top end snow totals landed pretty similar across most of our forecast zones, 8 to 12 inches, but the big discrepancy is where the rain line climbed to. Field observations and second-hand reports suggest the rain line topped out around 5,500 to 5,700 feet in the Northern Mountains but had a more extended period of time above 6,000 feet in the south. To our knowledge, this influenced conditions in slightly different ways.

During high-pressure that closed out 2025, the old snow surface evolved into a variety of forms - surface hoar and small faceted grains on shady and wind-sheltered areas, a thin melt-freeze crust capped sunny slopes, and harder layers were found in more wind-exposed areas. At the onset of snowfall last Friday, 2 to 4 inches of snow fell with generally light winds. This placed a nice blanket over the older snow surface helping preserve some weak, troublesome grains. Then the wind came along with rising snow levels. In our northern areas, initial rainfall was just enough to wet the surface and add extra weight to slabs, but rainfall in the south - while overall light - appears to have penetrated deeper into older snow layers and possibly disturbed those troublesome grains.

Observations over the weekend found increasing sensitivity where buried weak snow layers like surface hoar and facets remained preserved but were not happy with the added weight above. Throw in drifting of dense snow on the surface and snowpack tests started propagating in less than 24 hours from the rapid load - commonly failing in a layer of buried surface hoar. Where the water front made it deeper from prolonged rains, those looming layers below did not demonstrate the same increase in sensitivity from the new load. Regardless, this interface is shallow and easy to dig to and evaluate before making a final terrain decision.

What has been constant is faceted grains surrounding the Christmas-Grinch crust continue to perform despite the new flavor of snowpack weight. Observations in our northern and southern areas continue to report concerning results in failures in any one of the many faceted crust in the top 2 to 3 feet of the snowpack. Some tests will produce a propagating failure while another doesn’t, and compression tests vary between sudden collapse and sudden planar failures. This points to lingering potential for shallower failures to provoke a deeper failure and more dangerous avalanches. The caveat is natural avalanche activity has been almost non-existent and free feedback has almost disappeared as well.

Following such rapid snowpack change from varying types of water input (snow, rain, or wintry mix) and shallowly buried faceted grains, an extra cautions mindset remains prudent. Evaluate the consequences of the terrain you travel above, through, or below and how wide an avalanche could break. Now that mid and upper elevation start zones and slopes are more broadly connected, potential avalanche size increases with each new load as long as persistent weaknesses linger below. Places that have avoided recent rains and harbor a deeper overall snowpack, faceting in the snowpack has been less pronounced recently and individual layers there are better bonded.