Bollettino valanghe

East Slopes North

Northwest Avalanche Center
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Pericolo valanghe

Thu
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
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

As SE winds increase during the day,  shallow new winds will likely build below ridgelines.  With the change in wind direction, expect to find firmer wind-drifted snow on different aspects than earlier in the week.  Continuing the trend, even stronger winds along with light snow are expected Wednesday night. 

Problemi valanghivi

  • Wind Slabs

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

    This should be a good S through E wind event, but right now it looks like the new snowfall and strongest winds will hold off in the East North zone until Wednesday night/Thursday morning.  Be alert for shallow new wind slabs building on different aspects than what we have been looking for over the last few days.  Existing cornice lines may not be of much help Wednesday.  Watching for blowing snow along ridgelines and looking for new signs of instability, like shooting cracks in freshly drifted snow, will help tip off which slopes to steer around.

     

     

    Look for signs of blowing snow on the higher peaks and ridgelines to help identify which slopes are being loaded. 

    Photo: Katie Warren

    12/17/2022

Avalanche Discussion

In the Washington Pass area, it has been at least a week since several very large avalanches (D2.5-D3.5) released on persistent grains buried early last month.  These avalanches ran during the Christmas storm cycle (Dec 24-27th).  Recent snow profiles suggest that recent natural avalanches involved the Dec 8th buried surface hoar layer (2-3ft below the surface and below the Christmas crust) with at least one avalanche suspected to have run on sugar-like facets from November deeper in the snowpack.  A weak snowpack structure also exists in the Mazama environs and eastern foothills.   An observation from Willie Webster on 1/3 illustrates the weak snowpack structure in the Mazama area.  Throughout the zone,  the lack of recent avalanche activity and other signs of instability have increased our confidence that we can drop the persistent slab problem(s) for now.  We'll be waiting to see if future loading events bring these layers back to the forefront.  

Since New Year's Eve, recent avalanche activity has been much quieter.  Over this stretch a natural slab avalanche was observed directly below cliffs on Silver Star and professionals noted small dry loose avalanches on steep northerly aspects.  Last Friday (12/30), observers on Delancey Ridge experienced a large collapse at 6,500ft on a south aspect. They believe it may have been due to a deeper weak layer, possibly older facets from early season. 

Regioni coperte