Bollettino valanghe

Banner Summit

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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Non aggiornato — questo bollettino è scaduto 6 months ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Avalanche danger will increase throughout the day as a storm impacts the area. Triggering large avalanches is likely by the end of the day. Avoid slopes where the wind is rapidly depositing snow into cohesive slabs, and be prepared to dial back terrain choices if you're finding more than 6" of new snow.

Problemi valanghivi

  • Wind Slabs

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

    Expect to encounter freshly formed, sensitive wind slabs in terrain exposed to the wind. Some of these slabs are building atop crusts and facets. In these areas, slabs may be particularly sensitive and break wider than expected. Look for smooth pillows, dunes, waves, and textured surfaces of windblown snow near ridgelines, mid-slope gullies, and in cirques below large cliff bands. You may find wind slabs on open slopes at middle elevations as well, given the strength of the winds associated with the current storm. Cracks shooting from your skis or sled are a clear sign that you've found an unstable slab. These smaller avalanches can serve as an effective trigger for the much larger and more dangerous persistent slab problem described below. 

    ADDITIONAL DISCUSSION: Loose snow avalanches are possible during periods of intense snowfall. These could run faster and further than expected given the smooth, crusty surfaces present on many slopes before this storm.

    (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
    Unlikely
    Dimensione
    2

    Although unlikely, you could trigger a 2-3 ft thick persistent slab avalanche on buried weak layers (sugary facets, surface hoar, and crust + facet combinations). This problem is worst on middle and upper elevation slopes facing NW-N-NE-E. 

    Unfortunately, unstable slopes probably won't provide obvious signs of instability, like snowpack cracking or collapsing. Snowpack stability tests are likely to be inconclusive and are of limited use. Tracks on a slope don't mean it's safe. Avalanches can be triggered by the second, third, or fourth rider on a slope. In low probability/high consequence situations like this, there's a good chance the first sign of instability you'll see is the avalanche you trigger.

    The likelihood of triggering a slide is decreasing, but the thick, dense slab makes the consequences severe. Persistent weak layers can fail unpredictably and break wider and higher on slopes than you might expect. Avoiding avalanche terrain is the only surefire way to manage this problem. Short of that, you can reduce your risk by avoiding large avalanche paths and those with ugly consequences if you are caught in a slide.

    (3/6/2026)

    Small natural avalanche on a NE slope of Copper Mountain (S Summit) that pulled out mid-slope.

    Photo: Sawtooth Avalanche Center

Avalanche Discussion

This storm looks potent. Normally we think of large storm totals in terms of snow depth and SWE indicating a big storm, but not in this case. Instead, the potency is due to the strong to extreme W winds that are blowing throughout this storm cycle. Winds gusting up to 75 mph across most of our forecast area rarely occur, and sustaining those winds for 24+ hours is even more unusual. Additionally, spring storms are notoriously spotty in their distribution of snowfall, with intense squalls frequently dropping a few inches rapidly in specific locations. Expect to see unusual snow patterns and, potentially, unusual avalanche patterns due to these storm-specific factors. 

So how do we deal with this uncertainty in conditions? Build in larger margins for error. Last night, two of the forecasters, Ethan and Nick, gave a meaningful Digging Deeper presentation about an avalanche they were caught in earlier this year. One of their big take-homes was to build in larger margins when conditions are rapidly changing, especially if you're out on a snowing and blowing storm day. Use the forecast to lay a groundwork for safe travel if you are planning to venture into the mountains today, then be ready to read what's actually happening on the ground to dial back accordingly. Expect changing and deteriorating conditions throughout the day.

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