Lawinenlagebericht

Snoqualmie Pass

Northwest Avalanche Center
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Lawinengefahr

Thu
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
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Kernpunkte

You will encounter a lot of soft, deep snow as you travel around Snoqualmie Pass Wednesday. As the sun comes out, you may see the snow shedding from trees and rocks trigger very small loose sluffs. However, most of the real hazard lies on steep slopes below cornices and cliffs where the wind drifted the snow into firmer and thicker slabs.

Lawinenprobleme

  • Wind Slabs

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

    With all the low-density snow out there, even light winds may form new shallow slabs along ridges and exposed slopes. Most of these potential avalanches should be small and relatively easy to manage. Watch for drifts, sharp cornices, and stiffer snow to figure out which features might contain wind-loaded pockets. Don’t let these thin slabs catch you off guard in very steep or rocky terrain where even a small avalanche could hurt you. 

    While most wind slabs you encounter should be small and thin, several recent larger avalanches from across our region are at the front of our minds. Very large avalanches in wind-loaded snow were reported on Chair Peak (Snoqualmie Pass), Mt Mastif (Stevens Pass), and Shuksan Arm (West North) December 26-27. These slides highlight the potential for larger, much deeper avalanches, especially in rocky and complex terrain at upper elevations. While these slides would be hard to trigger, they would be catastrophic. Make sure to talk about this looming piece of uncertainty before stepping into big, high-consequence slopes.

    (12/28/2021)

    The crown of a very large avalanche in the upper Chair Peak Basin. This slide likely occurred overnight on Dec 25th into the 26th.  NE-E aspcet, 5800'. SS-N-R2-D2.5-U

    Photo: Dallas Glass

Avalanche Discussion

Snoqualmie pass received 4-5ft of snow over the past week. A strong cooling trend during the same time allowed this snow to generally fall right-side-up. As a result, in wind-sheltered areas, loose soft snow abounds. While we didn’t list it as an avalanche problem for Wednesday, you could encounter loose avalanches near very steep and rocky terrain. As the snow falls off trees and rocks, expect to see very small loose dry avalanches. If your travel plans take you into steep and rocky areas, don’t let these little avalanches knock you off your feet. 

Generally, 3-4 ft (90-120cm) of snow now rests above the Solstice Crust. While you can generally find storm interfaces in the snow, these layers haven’t produced any recent avalanches nor notable test results. A new very thin and breakable crust formed during the sunny weather on Monday 12/27 on steep sunny slopes. This could be a layer to keep an eye on and watch for faceting as we continue to experience very cold temperatures. 

We anticipate a change in the weather Thursday with slightly warming temperatures, increasing winds, and around a foot of snow. This should increase the avalanche danger, particularly at upper elevations. We’ve heard reports of weak snow (facets and surface hoar) developing at the surface around the region. Now, is the time to track it. While you travel Wednesday, make note if you see sugary facets or feathery surface hoar and send us your observation. This data may help as we head into another stormy period. 

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