Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
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Pericolo valanghe

Tue
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
1 · Debole
Open full map
Non aggiornato — questo bollettino è scaduto 2 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Down low you won’t find much avalanche hazard, but as you ascend to where the storm accumulated several inches of snow, the danger should quickly increase. You could encounter small natural slides or even trigger a larger slab. Give the new snow time to heal by staying off steep open slopes.

Problemi valanghivi

  • Storm Slabs

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

    Storm totals could reach a foot or more near 5000ft by Monday morning. Much of this new snow will fall with rising temperatures and moderate winds. To make matters worse these new slabs rest on a very firm and slick crust that could make them trigger very easily. With all these factors pointing towards unstable snow, assume steep open slopes could avalanche until you can prove otherwise. 

    Frequent hand pits, uptrack tests, and small slopes should give you a good idea of how the storm snow is behaving by aspect and elevation. When they fail easily or in blocks, avoid similar nearby terrain.

    These slides should only involve the snow down to the firm crust. This will help limit their size. However, in wind-loaded areas, that could result in much bigger avalanches a couple of feet thick.

    (1/11/2024)

    Example: Use small test slops, like the one in this photo to produce a mini avalanche. This indicates unstable snow. 

    Photo: Andy Harrington

  • Loose Wet

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

    You’ll need to manage two different versions of wet loose avalanches. Close the rain-snow line, wet heavy snow sits over the crust. In these places, instead of a slab you’ll probably trigger a loose avalanche. These will be most likely on very steep slopes. While easier to manage than the slabs, they could take you for a rough ride. 

    Sunshine in the morning could result in natural wet loose avalanches as snow sheds from rocks and trees. These slides will be most common on sunnier aspects (E-SE-S). Pay attention to what’s above you and don’t linger under sunny slopes once you start to see snowballs rolling down the hill. Increasing clouds around lunchtime should put this later issue to bed. 

    (4/13/2024)

    Example: Small natural wet loose slides like this could run as snow sheds from rocks and trees. 

    Photo: Andy Harrington

Avalanche Discussion

After a stormy Sunday night, things look very quiet to start the day on Monday. However, avalanche danger should be the highest right out of the gate and slowly decline as the snow has time to settle and bond to the underlying crust. 

Most reports from the Pass over the last few days emphasize a very stout (and growing) crust. The Solstice Crust at the base of the new snow is essentially “new ground.” We aren’t worried about deeper layers in the snowpack at this time. 

At lower elevations, the snowpack has been through a lot and is pretty beat up. There just isn’t enough new snow to create any real avalanche hazard. Instead, the travel conditions pose the greatest risk. One quote that summed up travel nicely, “I saw more water than snow.” Expect open creeks, frozen treebombs, downed debris, and thin coverage.

Regioni coperte