Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

Tuesday’s break in the storm should allow the likelihood for most avalanches to drop. However, multiple overlapping avalanche problems, known weak layers, and numerous recent slides should illicit a bit of caution. You can still trigger avalanches in very steep, convex, or unsupported terrain. 

Problemi valanghivi

  • Storm Slabs

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

    All the recent storm snow is settling and should be starting to heal. That doesn’t mean it won’t slide. The warming temperatures turned the new snow up-side-down. There are plenty of inter-storm layers due to changes in wind, snowfall rates, and temperature. It only gets more complex when you think of all the different surfaces the storm buried. You could find slick crusts or even surface hoar below all the new snow.

    This problem is easier to track. Hand pits, uptrack tests, and small slopes can all give you a window into how the new snow may behave. Make sure to dig down at least a foot or two to see all the new snow. Test that crack or result in blocks sliding should give you pause. 

    (2/16/2025)

    A widely breaking natural avalanche observed while riding out of the Gold Creek Snopark. This may have failed on buried surface hoar at the 2/13 interface.

    Photo: Josh Lipkowitz

  • Persistent Slabs

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

    This problem has been eerily quiet for more than a week. However, every time we look it’s still there and still appears weak and troubling. Two persistent weak layers buried roughly 3 feet deep have been well documented, however, there haven’t been any recent avalanches. This recent storm may not have caused the scales to tip, but it certainly did not help. 

    Don’t expect these layers to talk to you. The only way to see it will be to dig. While the likelihood is lower, these slides would be large and consequential. You’re most likely to encounter one of these avalanches on shaded complex terrain with plenty of rocks, rollovers, and other trigger points. Even though it’s deep, a small storm slab or loose avalanche could provide the weight needed to cause a slide.

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    It rained at the Pass on Monday. Boo! Near and below the rain-snow line the surface is wet and mushy. There probably won’t be many natural wet loose slides or rollerballs (they mostly happened Monday), but you still may trigger a wet slide. These push-o-lanches should be relatively small and easy to manage. But, if they catch you they might not let go and could carry you into a creek or over a cliff.

    (1/10/2025)

    Wet avalanches originating in steep rocky terrain after a rain-on-snow event earlier this winter.

    Photo: Andy Harrington

Avalanche Discussion

Tuesday’s break between storms should give the snowpack time to heal and us to take stock of the impacts from the recent storm. Gone are the days of blower powder at the Pass. We seem to have returned to a more Cascade normal snowpack. 

This last storm brought 1-2 feet of snow to the zone before the warm up. Multiple natural and human triggered  avalanches released on Sunday and Monday. Many involved all the new snow down to the 2/13 interface, while some on Monday only involved the most recent 3-6 inches The most notable was a very wide storm slab near Mt Margarett that we believe released on buried surface hoar. Not surprisingly, with the warming and rain, numerous wet loose avalanches ran on Monday.

Regioni coperte