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
Senza grado
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Non aggiornato — questo bollettino è scaduto 8 months ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

New snow accumulating overnight will fall on bare ground throughout much of the zone, limiting the overall avalanche hazard.  At upper elevations, wet loose avalanches are most likely to occur during the day as the snow transitions to rain.  With another round of rain, pay attention to the terrain that still harbors blocks of snow that could shed from steep rock faces. 

Problemi valanghivi

  • Loose Wet

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

    Normally, rain on fresh snow would drive the avalanche hazard higher than currently forecast.  That said, we don't typically have bare ground in mid-December at lower and mid-elevations. 

     6-12" of snow could fall Monday night and Tuesday before rain pushes into the upper elevations.  It's going to be tough to develop a meaningful avalanche hazard given our starting conditions with plenty of terrain anchors and bare ground.  If you're exploring out in this less-than-ideal weather, make sure a small avalanche couldn't knock you over cliffs or through rocks/trees; there are plenty of those right now.   Small wet avalanches can occur on steep smooth slopes, i.e. smooth slopes that already have snow.  Any blocks of snow still clinging to steep rock faces present an overhead hazard and can shed at any time with more warmth/rain on the way.  

    Example photo: A small wet loose avalanche in thin snow cover, running down to the ground. 

    Photo: Irene Henninger

Avalanche Discussion

Snoqualmie Pass blew right through the forecast, picking up over 3" of rain during the day on Monday.  Winds at the top of Alpental accompanied the torrential rain with consecutive hours of gusts in the 90s.  All of this wild weather didn't lead any new avalanche hazard due to the lack of snow.  Alpental professionals on the upper mountain reported that the snowpack had taken a beating and had become much more discontinuous since Friday.   Things are going to change this week, and hopefully we'll be talking about travel over snow vs foot soon enough.  

If you do head out into the mountains, please slow down and be aware of potential overlapping natural hazards: landslides, washouts, flooding, and downed trees.  It will take some time to fully catalog the changes in the landscape following our extended period of extreme weather. 

With the warm start to the 25-26 winter season, we have less snowpack information than usual to start daily forecast operations. For zones and elevation bands with less snow than needed for avalanche hazard, we will issue a forecast with No Rating. Anticipated avalanche and weather conditions will still be updated daily. NWAC will issue an avalanche danger rating for a zone when enough snow to produce avalanches has accumulated at middle and upper elevations.

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