Lawinenlagebericht

Silver Valley & Bitterroot Mountains

Idaho Panhandle Avalanche Center
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Lawinengefahr

Mon
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
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Kernpunkte

Wind will continue to transport the new snow into cohesive slabs below ridgetops and along steep gully walls, which will also increase slab depths that are overlying concerning weak layers. Not all danger ratings are equal, and Sunday’s MODERATE (2of5) is just a half step away from CONSIDERABLE (3of5). Conservative terrain choices will be essential to avoid triggering a large and dangerous avalanche.

Lawinenprobleme

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    Slabs 1 to 2 feet thick sit above buried weak layers of surface hoar, faceted snow, and hard crusts. Light but steady snowfall over the last two weeks has gradually overloaded these weaknesses, creating a concerning snowpack structure. The character and distribution of these weak snow layers varies between our northern and southern areas, and subtle differences even exist within the same mountain ranges. The differences reflect variations in rain–snow elevations, storm totals, aspect, and periods of warm, sunny weather. 

    Knowing exactly what load is needed to break the camels back is challenging to pinpoint, but a practical benchmark is new snow amounts. Slopes where you find around 6 inches or more of new snow, it's time to reassess your plan and give avalanche terrain a wider margin. The current structure is particularly problematic because the main evidence of instability we’ve observed is ongoing propagating failures in tests, while obvious warning signs like recent avalanches, cracking, or collapsing have been less frequent. Travel with a conservative mindset and favor slopes around 30 degrees without steeper hazards above.

    New snow will build on a weak surface and previously buried weak layers that have been producing propagating results in large column tests. 

    February 12, 2026. 

    Photo: Izzy Davis

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–1.5

    Storm totals range 4 to 7 inches in the Silver Valley-Bitterroot Mountains. In wind-drifted terrain like areas directly underneath the ridgeline and on steep gully walls the new snow will be more reactive. Avalanches triggered in the new snow may only fail at the new/ old snow interface, but knowing what looms deeper is enough to hedge a bet that shallow slides equate to deeper, more dangerous ones. Give the new snow time to settle and avoid traveling on slopes around 35 degrees or steeper, and where you see cracking, hear audible collapses, or feel a transition in the snow surface from soft to firm and hollow-sounding.

    A textured surface, shooting cracks, and a transition from soft snow to denser snow are all clues that the wind has stiffened the new snow into cohesive slabs. 

    February 9, 2026.

    Photo: Izzy Davis

Avalanche Discussion

Two-day snow totals range 6 to 7 inches in the Selkirk Mountains, 5 to 8 inches in the Cabinet Mountains, and 3 to 4 inches in the Bitterroot Mountains. Snow densities were just north of 10 percent and almost an inch of Snow Water Equivalent at most SNOTELs.

With a break in the snowfall action today for most areas, fresh slabs will get a chance to settle and we anticipate them to be less reactive as yesterday. Less reactive is much different than unreactive so continue to be wary of slopes with around 6 inches of new snow. Slopes with deeper snowfall or where winds stiffened these fresh slabs, those places are where we expect sensitivity to stay elevated longer and ensuing slides will be larger.

If you trigger a slide that stays confined to the new snow, consider yourself lucky. Below the new snow is a complex snowpack structure that has lots of variability between individual forecast zones and within the same ones. Primary concerns lie 30 to 60 cm below the surface and carry big consequences because of how widespread the weaknesses are. The variable that has arrived at inconsistent time frames is slab depth. By and large the most worrisome elevations to find trouble are between about 5,500 and up to the slope-specific treeline. In that elevation range, that is where buried surface hoar is the largest, remains relatively intact, and has the largest hardness step compared to the slab above and the planar surface it sits on.

If you manage the terrain through middle elevations appropriately and into upper elevations, observations recently have noted much better upper snowpack layer bonding. Still, the slab sits above a very firm, slippery rain crust capped with small facets above and below the crust. This interface, like the surface hoar below, is found across all aspects at upper elevations and all the way to mountain tops. While evidence suggests deeper buried concerns in more wind-exposed areas are less worrisome than in shady, wind-sheltered terrain, the broad breaking potential of avalanches higher up should be factored into your terrain selections.

Lower elevations have returned to a similar shallow, patchy snowpack state of affairs as earlier in the season. The recent warm periods between storms have depleted a lot of snow depth below 5,500 feet and we likely need more snow volume to move the avalanche needle upward there. That may come over the next 24 to 36 hours as snow levels are projected to lower and slabs of snow form over a refrozen rain soaked snowpack.

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