Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
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Pericolo valanghe

Wed
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 5 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Fresh wind slabs may form on lee slopes at upper elevations Tuesday.  Use caution below ridgelines where you find freshly drifted snow.  While glide avalanches are unlikely with a return to cooler conditions, continue to limit your exposure below any steep slope with recently formed glide cracks.  

Problemi valanghivi

  • Wind Slabs

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

    This storm might squeak out enough new snow and wind to create a wind slab problem at upper elevations Tuesday.  Use caution on slopes where you find freshly drifted snow.  Watch for blowing snow along ridgelines to see where wind slabs may have developed.  If you observe cracking in the new snow, you may trigger a small wind slab avalanche on similar slopes.  At mid-elevations, you'll likely find up to a few inches of wet snow bonding well to the old snow surface and hopefully, improving travel conditions.  

    You may find new shallow wind slabs above treeline Tuesday that have bonded poorly to the old crust.  Use small test slopes to test the bond of the new snow to the old snow surface.

    Photo: Matt Lubar- Baker Mtn Guides

Avalanche Discussion

Rain at lower elevations is unlikely to cause an uptick in the likelihood of loose wet avalanches. The snowpack is quite beat up and can handle some light rain.  However, you need to still have glide avalanches on your mind for another day or so in the Snoqualmie zone.  The last observed large glide avalanche occurred on Sunday, triggered by Alpental pro-patrol during avalanche mitigation.  Observers reported crevasse-style glide cracks on nearly every slope over the last few days.  Glide avalanches are hard to predict and can often occur days after the heaviest rain or warmest temperatures.  Continue to limit your time below steep rocky slopes with glide cracks. 

Observers reported firm crusts of varying thicknesses (most ski supportable, some boot) throughout the Snoqualmie Pass zone over the holiday weekend.  Take care when crossing steep slopes if you find icy conditions and near terrain traps that would amplify the consequences of a slip and fall.    

Major avalanche cycles occurred Jan 6-7 and Jan 11-12,  and thoroughly tested the snowpack with evidence of large and very large avalanches visible throughout the landscape from these cycles. Below the surface alternating layers of firm crusts, weak wet snow, and strong rounded grains exist. At the moment we aren’t tracking any layers of concern in the upper snowpack. 

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