Lawinenlagebericht

Stevens Pass

Northwest Avalanche Center
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Lawinengefahr

Tue
Hochgebirge
3 · Erheblich
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
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Kernpunkte

The snow is piling up, and it's becoming more likely to trigger avalanches where the wind drifts snow into thick slabs. You're particularly likely to trigger larger, more dangerous avalanches at upper elevations on steep slopes below ridgelines. Choose wind-sheltered terrain or avoid steep slopes where you identify deep pillow-like drifts. 

Lawinenprobleme

  • Wind Slabs

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

    While you might not see many natural avalanches throughout the terrain, you could be quite likely to trigger a large and dangerous wind slab, particularly at upper elevations in alpine terrain. Look for deep, stiff drifts below corniced ridgelines or textured surfaces to identify wind-loaded slopes. You can use small convexities within lower-angle terrain to assess how wind-affected snow reacts to a load. Cracks that shoot away from your equipment indicate dangerous avalanche conditions. Your best option is to avoid steep wind-loaded slopes at mid and upper elevations and consider wind-sheltered terrain instead.

    Over the last 48 hours, the Stevens zone has received over 1 foot of new snow, and more is coming for Monday. With this much new snow, you may also trigger smaller storm slabs or dry loose avalanches. While these are likely to be smaller, they can have high consequences with many exposed obstacles in the thin snow cover. Try small test slopes to observe how the snow reacts before committing to larger, more consequential terrain. The zone has significant variability from west to east, so pay close attention to snow depths as you travel. Where you find more recent snow, avalanches will be larger and more dangerous. 

    (12/15/2024)Reactive wind slabs at upper elevations in the Stevens Pass zone on Sunday.6300ft, N aspect 

    Photo: Ryan Minton

Avalanche Discussion

An early Christmas present brought more snow to the Stevens zone than anticipated on Sunday. While none of this weekend's storms have been impressive by Pacific Northwest standards, we have 12-18 inches of fresh snow at mid-elevations throughout the zone, and upper elevations probably have closer to 2 feet. We can expect another modest amount of fresh snow on Monday along with moderate winds. 

The recent storm snow fell with cooling temperatures and lacked a cohesive slab structure in sheltered terrain. However, backcountry observers and the Stevens Pass Patrol reported sensitive wind slabs over the weekend. Most avalanches were small, but some were large enough to bury a person in steep, wind-loaded areas. 

The 12/7 melt-freeze crust is now buried 2-3 feet deep, and observations throughout the zone have shown a favorable bond with this layer. The lower snowpack consists of moist or refrozen melt forms, while the mid and upper snowpack is mostly the recent storm snow. A melt-freeze crust formed early in the week on southerly aspects is now buried 10-15 inches deep. This crust doesn't exist on northern aspects. However, on Sunday, I was out on northern aspects in the Henry Creek drainage and found a layer of buried surface hoar on this interface (12/13). This layer showed reactivity in stability tests, but the recent snow lacked enough structure to produce shooting cracks on test slopes. 

Travel below 4000ft is still challenging with very low snow cover and it gets worse further east in the zone. At 4000ft in Henry Creek, I found just under 2 feet of snow. 

If you get out in the backcountry, please consider SUBMITTING AN OBSERVATION and help shape the avalanche forecast. 

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