Bollettino valanghe

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Sawtooth Avalanche Center
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Pericolo valanghe

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

Conditions are dangerous at upper elevations. Expect to trigger a large, 1-4 foot thick avalanche on wind-affected slopes. Slides are also possible on some wind-sheltered slopes. Avalanches may be triggered remotely—from gentler terrain above, below, and to the sides of steep slopes.

Problemi valanghivi

  • Wind Slabs

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

    You are likely to trigger a wind slab avalanche in upper elevation, wind-affected terrain. Consistent windspeeds ideal for moving snow, combined with plenty of new snow overnight, created sensitive wind slabs in exposed terrain. Expect to find these firm slabs in most alpine locations, on the aprons of chutes, near ridgelines and along cross-slope gullies. Given the strength of the overnight and forecasted wind today, wind slabs may also be found in isolated pockets in open middle-elevation terrain.

    If you see cracks shooting out from your machine or boards - take it as a sign to move to slopes with softer, less cohesive snow on the surface. Look for blowing snow and drifts and feel for firm, smooth, rounded, and hollow surfaces as indicators that the wind has been at work.

    These wind slabs sit on top of various persistent weak layers and could break more widely than expected or act as triggers for larger, deeper, more destructive avalanches (described below).

    (2/25/2026)

    A pair of large natural avalanches on a NE aspect at 8800' along the ridgeline between the two Copper Mountain summits. Clear evidence of wind loading and cornice growth is obvious in this photo as well.

    Photo: Sawtooth Avalanche Center

  • Persistent Slabs

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

    Weak snow sits underneath 1 to 4 ft slabs of consolidated snow on many slopes and is further hidden by a fresh layer of new storm snow today. These overlying slabs are thickest, stiffest, and most widespread in middle and upper-elevation winded terrain, and yet most sheltered slopes also harbor softer cohesive slabs resting over weaker snow. There are various buried weak layers, including sugary facets, surface hoar, and crust + facet combinations, that are most easily identified by digging into the snow. These are primarily found on NW-N-NE-E aspects, though they also exist, more variably, on the margins of sunnier aspects.

    Avoiding avalanche terrain where you suspect these weak layers to be lingering under the surface, especially in wind-affected areas, is the best way to stack the odds in your favor. Determining whether a given slope is safe to ride or just waiting for a trigger—you— is challenging. Due to the variable distribution and character of both the slabs and weak layers, stability can change quickly over short distances. Recognize that these avalanches may be triggered remotely - from above, below, and to the sides. You may or may not observe clear signs of unstable conditions, such as snowpack cracking and collapsing, before triggering a slide.

Avalanche Discussion

Sometimes weak layers are overloaded by a large storm, leading to an obvious spike in avalanche danger. Our recent loading pattern has been more insidious, with a number of 4-8" storms incrementally adding weight to layers of sugary facets, surface hoar and facet+crust combinations. With each small loading event, we watch for the “canaries in the coal mine”—indications that the snowpack is reaching its breaking point. Each of our recent storms has been accompanied by a corresponding avalanche cycle, and we expect the same today. Given the relatively small storm, we expect most avalanches to fail as medium to large wind slabs, but there's a fair amount of uncertainty about the reactivity of the buried persistent weak layers. Small to large "new snow" avalanches and/or active wind loading could easily be the larger "thump" those buried weak layers need to wake-up and we won't be surprised if we see a variety of deeper, larger avalanches. Be thinking about if you're seeing those canaries.

Keeping to slopes with soft snow on the surface and no buried persistent weak layers should make for great riding today! Just remember that conditions are more dangerous than they have been, and take a conservative mindset.

Regioni coperte