Lawinenlagebericht

Snoqualmie Pass

Northwest Avalanche Center
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Lawinengefahr

Sat
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
2 · Mässig
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Kernpunkte

A wet snowpack, warm sunny weather, and the potential for very large avalanches should make you think about where you want to travel at Snoqualmie Pass. Wet slides could start on large, very steep, and rocky slopes. So, choose routes that limit the amount of time you spend under these very specific features.

Lawinenprobleme

  • Glide Cracks

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Unlikely
    Größe
    2–3

    Several local avalanche professionals gave similar reports, “there are glide cracks everywhere!” These crevasse-like features indicate the settling and gliding of the snowpack downhill in steep terrain. Sometimes these same slopes suddenly fail and produce avalanches. The tricky part about glide events is that they don’t always time with peak precipitation or warming like many of our other avalanche problems. They can sometimes occur days after the rain stopped. This makes them notoriously difficult to predict. Combine that with their potential to produce very large and destructive slides, and you have the makings of a very challenging problem. While these avalanches are unlikely, being caught in a glide avalanche would almost certainly be fatal. Limit the amount of time you spend under large, steep, and rocky slopes (especially when you see glide cracks) where these high consequence avalanches may occur.

    (1/13/2022)

    Glide cracks abound on many steep slopes at Snoqualmie Pass. These crevasse-like features indicate the settling and gliding motion of the snowpack. Sometimes, these same slopes give way without warning and produce glide avalanches. 

    Photo: Robin Pendry

  • Loose Wet

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    In some locations, you may find the snow surface frozen in the morning. This could help delay but not eliminate the loose wet avalanche hazard. Warm sunny weather will weaken the snow surface and could produce loose avalanches. When you find the snow is wet and unsupportable, it’s time to seek out lower angle or more frozen slopes. Rollerballs and small point-release slides are great indicators that the warm weather is winning and causing the snowpack to become wet and unstable. While most of these slides should remain small, in bigger terrain they may gather additional snow and grow large enough to bury you. While you could encounter loose wet avalanches anywhere, sunshine may cause these slides to be most prevalent on SE-SW aspects. 

    Even though we’re focussing on Glide and Loose wet avalanches, wet slab and natural cornice events could still occur. With all the recent rain and warming temperatures, expect this combination of wet avalanche issues to linger longer than you might normally expect. This includes the chance for isolated natural avalanches.

    (1/13/2022)

    Nope, this isn't a snowpit. The wet surface snow is weak and unsupportable. If you find the surface crust breaking down, anticipate an increase in the wet potential for wet avalanches. 

    Photo: Andy Harrington

Avalanche Discussion

This isn’t our normal weather and avalanche cycle. Several factors stand out making it unique and challenging to predict. 

  • Prolonged warming will continue on Friday, however, temperature inversions and long cold clear winter nights may allow some slopes to freeze more solidly than others. 
  • Snoqualmie Pass just received more than 4” of water (mostly as rain) 1/11-12. Some of this water is still making its way through the snowpack and due to the warm temperatures has not frozen. 
  • We also just experienced two notable avalanche cycles. The first (Jan 6-7) resulted in numerous D2s and several very large (D3-D4) avalanches. The more recent (Jan 11-12) produce several wet slab, glide, and loose wet slides. 

So, the snowpack has been recently tested and produced plenty of avalanches, however, the current weather pattern isn’t allowing the danger to drop. As a result, the potential of wet slides continues to linger. 

Observations of the upper snowpack show alternating layers of wet snow and crusts. About two feet (60cm) below the surface dry snow can still be found, however, no layers of concern have been identified. What does this tell us? The snowpack is still in transition and adapting to the recent big changes. 

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