Bollettino valanghe

Galena Summit & Eastern Mtns

Sawtooth Avalanche Center
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Pericolo valanghe

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Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
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In sintesi

Conditions become most dangerous as you climb into exposed, windy terrain. There, you are likely to trigger avalanches involving either recent drifts or the entire snowpack. You may be able to trigger avalanches remotely—from flat terrain below, above, and to the sides of steep slopes.

Problemi valanghivi

  • Persistent Slabs

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

    Triggering thick, meaty slabs remains likely on wind-affected middle and upper elevation slopes, and is possible in sheltered terrain. Slabs may fail on either weak, sugary facets buried 2-5 feet deep or on crusts or storm interfaces in the upper 3 feet of the snowpack.

    The facets: Faceted snow is buried near the ground on W-NW-N-NE-E-SE-facing slopes at middle and upper elevations, and the facets need some time without snowfall or wind-loading to strengthen. Many large to monstrous-sized avalanches released naturally since Christmas Eve (view a list of recent avalanches and photos here). Many of these avalanches would have been unsurvivable. You're most likely to trigger destructive slides on facets near the ground 1) in windy and/or rocky areas where the snowpack depth is variable and 2) in more sheltered terrain where the snowpack depth is about 3 feet deep. 

    The crusts: Multiple storm interfaces and rain and temperature crusts are now buried about 1-3 feet deep. Triggering avalanches involving the crusts and interfaces (photo) is most likely on slopes where the wind drifted snow or stiffened the snow surface.   

    How can we manage this problem? Sadly, avoidance is still the best option to reduce your risk, especially on wind-loaded slopes. Assume the slab + potential weak layer setup exists on all slopes until you dig in the snow to prove otherwise. You may or may not experience obvious signs of instability—like snowpack collapsing or cracks shooting out from your skis or sled—before triggering an avalanche. 

    (12/24/2025) This very large avalanche was remotely triggered from low-angle terrain adjacent to a large alpine bowl. Spring Ck in the Boulder Mountains. NW @ 10,200'. Photo: Ben VandenBos

  • Wind Slabs

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

    Recent strong winds formed hard and soft slabs up to 3 feet thick in upper and some middle elevation locations. Watch for smooth pillows, dunes, and large wind features below ridgelines and cornices, on the sides of cross-loaded gullies, and below large cliff faces and chutes in alpine terrain. Hard slabs may feel hollow and sound like a drum as you move across them. 

    How can we manage this problem? The fresh wind slabs are easy to spot and avoid. Cracks shooting out from your skis or sled are an obvious sign that you've found a wind slab. Hard wind slabs behave unpredictably; they can break above you and wider than expected. Small Wind Slab avalanches could trigger the much larger Persistent Slabs as the slide moves downslope. 

    (12/18/2025) Natural wind slab avalanches on a NE-facing slope near 8900' on Copper Mountain. Photo: Sawtooth Avalanche Center

Avalanche Discussion

Large, destructive avalanches (see photos below) remain likely in wind-loaded terrain and / or where the snowpack is relatively thin. Recently wind-loaded slopes where the snowpack is also thin are especially sketchy; you can trigger these hard slabs on the edges of slopes where the slab thins. 

Yesterday, strong wind made conditions downright unpleasant in upper elevation terrain on Copper Mountain to the north of this zone. There, surface conditions changed dramatically in exposed, upper elevation terrain; hard slabs, scoured slopes, and overbuilt wind whales and features became common. The snowpack could behave unpredictably once you enter windier environments. 

In sheltered terrain, the highest odds of finding an unstable slope are where the snowpack is around 3 feet deep: not too thick, and not too thin. Likely "3 foot deep" areas include middle elevation slopes in the White Clouds, near Tornak and Coyote Yurts, in the Warm Springs Drainage, and terrain on either side of highway 75 near and south of Prairie Ck. 

 

 

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