Lawinenlagebericht

Silver Valley & Bitterroot Mountains

Idaho Panhandle Avalanche Center
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Lawinengefahr

Mon
Hochgebirge
2 · Mässig
Waldgrenze
1 · Gering
Unterhalb
Keine Stufe
Veraltet — dieser Lagebericht ist 8 months ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

The rollercoaster of wild weather, challenging access conditions, and a wide range in snow depths across the same forecast zones all contribute to a higher degree of uncertainty than normal. We do know that new snow and elevated wind speeds will work together to form wind slabs below ridgelines and around steep terrain features, such as gully walls, which can catch the transporting snow. The best way to manage the higher degree of uncertainty is by diligently monitoring the conditions in front of you and adapting travel plans to changes. Classic red flags, like cracking within the new snow and density changes underfoot, warrant seeking lower-angle slopes that are sheltered from the wind.

Lawinenprobleme

  • Wind Slabs

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

    Snow totals in the previous 24 hours range between 2 to 4 inches, with snowfall in the mountains continuing today. This incremental loading will be met with moderate wind speeds from the west-southwest that are strong enough to drift the snow into growing wind slabs. Although these slabs are expected to be small, they have a greater consequence if they knock you off your feet and sweep you into low-coverage areas. The most likely places to encounter slabs will be below northerly and easterly-facing ridgelines at upper elevations, and around steep terrain features that collect drifted snow.

    These slabs will be developing on a rain crust that formed late Thursday night and Friday morning. There is some uncertainty surrounding what elevation the rain reached, but recent observations show that rain advanced to over 6,000 feet and approached above tree line elevations. If you work your way into higher elevation slopes and notice the rain crust disappear, that’s a good indicator that slabs may be thicker and could break deeper into the snowpack. 

    A glassy sheen on the snow surface after a rain on snow event mixed with blustery winds. This slick surface will be what today's snowfall will be building on.

    December 19, 2025.

    Photo: Jackson George

Avalanche Discussion

Nailing down conditions is a challenge at present. This is a function from frequent oscillations between snow and rain, varying amounts of each precipitation flavor, and broad elevation extent of snow cover. Throw in other non-snow logistical challenges like many downed trees, washed out road access, and frankly…no snow to travel the long distances necessary to access the plentiful snowpack and this leaves lots of assumptive thoughts on the table. All of this makes it hard to call a spade a spade.

Field teams over the past two days had high hopes of accessing the mountains to assess the upper extent of Thursday night’s rain and look for soft snow conditions, and evaluate upper snowpack layering. These dreams were quickly dampened by the presence of a robust rain crust from rain exceeding 6,000 feet…again…or not making it to the starting spot due to other access factors out of their control.

Thankfully, snowfall continues in the mountains and the snow line forecast looks slightly more promising than it has been. Although, we will believe it when we see it and really need the snow line to drop lower in elevation to help the cause.

If you are motivated to navigate conditions at lower elevations and reach the continuous snow line, avalanche concerns will likely be confined to wind-drifted slabs sitting above the upper most rain crust. Prior, older crusts exist in the top two to three feet of the snowpack and our limited field observations have noted them breaking down and faceting. We still think bigger snow loads are needed for deeper failures, but if you push above the most recent rain line, the scenario and end consequence is likely different. Places that avoided Thursday’s rain will harbor thicker and more cohesive slabs of snow sitting above…another crust…that have potential to produce a larger, more dangerous slide. The unfortunate part is we don’t know exactly what that elevation is and it likely varies between our forecast zones.

Digging down as you travel around the mountains - especially at higher elevations - is the only way to paint a better picture of what’s below your feet. If you encounter noticeable snow surface hardness changes or see phat, lens-shaped pillowy areas, pivot your travels to lower-angled slopes or ones without steeper overhead hazards. And while you’re at it, burn a pair of old skis to help out the meager snow conditions.

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