Bollettino valanghe

Stevens Pass

Northwest Avalanche Center
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Pericolo valanghe

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

Heavy snow and strong winds formed deep slabs where you can easily trigger large avalanches. The most dangerous places will be upper elevations and steep slopes with deep wind drifts, where avalanches could be large enough to break trees. Reduce your risk by sticking to low angle, wind-sheltered slopes. 

Problemi valanghivi

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    2–2.5

    Yet another pulse of heavy snow is headed our way, continuing to build reactive storm and wind slabs. At upper elevations, avalanches could step down to deeply buried weak layers and become very large. Avoid traveling on or under steep alpine bowls, where there is a chance for isolated, very large natural avalanches. Seek out wind-sheltered terrain, and if you observe signs of instability, such as cracking or recent avalanches, choose low-angle slopes. Avoid any steep terrain with deep wind drifts. You could trigger an avalanche on many steep slopes, but avalanches on steep wind-loaded slopes are likely significantly easier to trigger and much larger. You can identify wind-loaded terrain using visual clues such as drifts and textured surfaces. With the extreme wind speeds over the past 24 hours, wind slabs may be in unusual locations, farther downslope, or in typically sheltered terrain. 

    (3/11/2026)

    Notice the debris and long cracks extending far downslope in this low-angle terrain. This is a classic red flag for unstable storm slabs. 

    Photo: Josh Hirshberg

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2.5–3

    We have limited information from upper elevations, but these powerful storms could have reawakened deeply buried weak layers. We still expect this problem to be difficult to trigger, and avalanches may be more isolated. But given the uncertainty and high consequence, give yourself wide terrain margins around steep alpine bowls. A natural avalanche large enough to damage a house wouldn't be out of the question. These slides could run long distances into lower elevations and break widely across terrain features. Avoid traveling on or under steep open terrain at upper elevations. 

    The same loading that's creating widespread storm and wind slabs is also stressing older weak layers. You can find layers of facets and buried surface hoar just above a couple of crusts about 4-5 feet below the surface.

    (2/28/2026)

    Multiple widely breaking avalanches (up to D2.5) on the southeast aspect of the South Peak of Rock Mtn. SE-S, 5,800ft-6,600ft

    Photo: Josh Hirshberg

Avalanche Discussion

Wednesday night, a widespread natural avalanche cycle occurred, and rain reached well into the middle elevation band. Temperatures quickly fell back down below freezing, and now this rain crust is buried by 12" of snow, with another 10-12" on the way. Elevations above 5800ft likely stayed as snow. 

With 3-4ft of snow over the week, consider the consequences of deep snow immersion. Tree wells and creek holes can be very dangerous in these conditions. Make sure to keep close tabs on your partners in case you need to perform a rescue. 

An NWAC forecaster and other snow professionals out on Wednesday reported widespread touchy storm slab avalanches. Avalanches were triggered remotely and broke widely around terrain features. On Tuesday, two snowboarders were caught and carried in a storm slab that failed on a crust 2-2.5' deep. These are dynamic and active storms with rapidly changing conditions. Make sure to keep a conservative mindset and wide margins with your terrain selection.

At upper elevations, we have limited information, but we suspect that older weak layers remain active, and this ongoing storm is the first true test.  Given the ongoing loading, avalanches on these weak layers could now be more likely. But we won't know much about this problem until after the storm passes. So treat these weak snow layers as highly suspect until we can reduce the uncertainty. 

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