Bollettino valanghe

Selkirk Mountains

Idaho Panhandle Avalanche Center
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Pericolo valanghe

Mon
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 7 months ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Today’s MODERATE (2of5) danger is not that much different from yesterday’s CONSIDERABLE (3of5) danger where the same dangerous consequence of triggering an avalanche hangs around. While the chance to impact weaker layers below diminishes with time like the absence of signs of unstable snow, all it takes is finding the shallow, not-so-sweet spot to provoke a slide that grows large enough to expand above you or to adjacent slopes. Your best course of action is to choose slopes less than about 35 degrees that provide you with a wide buffer below steeper overhead hazards and avalanche paths.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Westerly winds continue to blow hard enough at upper elevations to transport the abundant low-density snow onto leeward slopes and into thicker, stiffer slabs. The most sensitive slabs will form directly below ridgelines and in steep mid-slope terrain features prone to cross-loading. These slabs will feel dense and often form downwind of places with a textured snow surface. 

    Heed the warning signs of shooting cracks in front of your boards or machine and go around places that look smooth and rounded. Avalanches triggered in the drifted part of the slope have the potential to step down into deeper layers, and those avalanches will grow larger in size and be more difficult to escape.

    SS-ASu-R1-D1-S. Very small skier triggered wind slab avalanche on cross loaded mid-slope terrain feature. Crack propagated into adjacent gully from apex of skier turn. Crown grew from 5 inches where initiated to 8 inches. Soft wind slab turned to loose dry sluff once moving.

    Photo: Mikey Church

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–3

    Throughout our forecast areas, slabs two to three feet deep rest on top of a variety of weak snow layers in the upper snowpack. There are subtle variations in the size, distribution, and sensitivity of weak snow concerns across individual forecast zones, and the primary layer of concern is different depending on whether you’re travelling in the Northern or Southern Mountain region.

    A widespread surface hoar event occurred around January 1 and was promptly capped by a 3 to 4 inch layer of light snow in the Northern Mountains helping preserve these feathers. During the same storm, the rain line climbed higher in elevation in the Silver-Valley Bitterroots helping to destroy or lessen the broader extent of these feathers. As a result, the layer of surface hoar remains the primary culprit of deeper snowpack failures in the Selkirk and West Cabinet Mountains. This layer lingers at mid and upper elevations, across most aspects, and continues to produce propagating failures in tests. 

    The primary layer of concern in the Silver Valley-Bitterroots is the faceted Grinch crust that developed on Christmas and has weak grains both above and below it. This layer recently has been trending toward less reactive now that a thick, dense slab is helping compress layers above the crust. This shifts the triggering concerns of this weak interface toward shallower areas of slopes that face northerly and easterly. An avalanche in either one of these weak layers could evolve into a high-consequence, potentially deadly scenario.

    Annotated photo of snowpack layers and test results on a northwest aspect near 6,300 feet, with propagating results on the early January surface hoar.

    West Cabinet Mountains, January 9, 2026.

    Photo: Chris Bilbrey

Avalanche Discussion

Avalanche conditions continue to slowly ease down from the window of peak instability. This is being influenced by the lack of new snow load and less drifting and which is allowing the snowpack to find some equilibrium. However, the process of finding balance is happening faster closer to the surface than deeper within. While conditions seem quiet from our above the surface perspective, potentially deadly concerns lie quietly only waiting for a tickle in the right or wrong spot - depending on how you look at it.

Not to sound totally doom and gloom, but the last storm cycle could eventually turn into a positive event for overall conditions. The transition from reactive to stubborn to unreactive weak snow layers will undoubtedly take more time and slab strengthening which helps diminish signs of unstable snow can push us toward a false-stable assessment of conditions. Meaning, the places where we can impact weak snow below become more isolated in a broader sense, though the threat is not fully eliminated. 

When this occurs, we need to incorporate other tools in the bag of assessment. If our digging-testing evaluations highlight failure potential in any flavor of weak snow less than about 3 feet deep, we need to factor consequences of triggering an avalanche into our decision-making process. As we move further away from the main snowpack strain loading event, we may evolve into a situation where multiple riders or machines could travel on a slope before the golden beebee finds the spot. This means making conscious decisions about where you travel in the terrain, how many people are on the slope at once, and identifying areas of safety with wide margins.

Buried surface hoar is one of those persistent grains that should be given the respect that is due. These feathers can have very similar distributions across similar types of slopes but can also vary enough spatially between neighboring drainages and in micro-areas of a range to behave differently. They will also sit patiently for longer periods of time to where we often forget about them to only rear their ugly heads when our hackles have laid down.

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