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
1 · Debole
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Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Westerly winds kept up through Monday, and you could still trigger avalanches in pockets of wind drifted snow. The most likely terrain to trigger one of these avalanches would be very steep ridges or exposed alpine terrain. Look for these smooth, pillowlike drifts and steer around these features where you find them on steep slopes. 

Problemi valanghivi

  • Wind Slabs

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

    There were multiple reports of skier trigger winds slabs on Sunday, and the westerly winds continued to gust throughout the day on Monday. So you can anticipate lingering pockets of unstable wind slabs on Tuesday. We expect most of these avalanches to be small and are becoming more difficult to trigger. However, don't let your guard down in steep terrain near ridges, rocks, cliffs, and confined features where even small avalanches could have high consequences. Cornice features, textured surfaces, and stiff snow over softer snow are all ways to identify wind slabs. Before committing to steep slopes in wind exposed areas, look for signs of instability in small test slopes, such as long shooting cracks. If you identify any signs of unstable snow, steer around these stiff pillowlike slabs or stick to lower angle and less consequential terrain. 

    (1/7/2023)

    Small wind loaded test slopes can show you how reactive wind slabs are likely to be. Like this one that cracked and failed. 

    Photo: Dallas Glass

Avalanche Discussion

Observations indicated that while the recent snow became increasingly heavy on Monday, the sun only crept out for a few hours. While wet loose avalanches didn't truly develop in this short sunny period, a new thin crust may have formed on steep south aspects.The recent snow is stacking up on various surfaces and burying the MLK crust deeper. Before this storm, slopes in the direct sun had a thin sun crust, while shadier terrain preserved some weaker surfaces. Before stepping out into more committing or steep terrain on Monday, take a minute to check the bonding of the new snow to the old surface to see if it fails easily wherever you're recreating. Slopes with a weak interface between the old and new snow layer could break wider than anticipated. On slopes with a sun crust, a bed surface may now exist for avalanches to run far and fast, whether that's in loose form or as a slab. Any avalanche should only include the snow above the MLK crust (about 1.5-2 feet below the surface), and the majority should revolve around the new storm snow.

Regioni coperte