Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Plenty of recent snow, coupled with increasing winds, will maintain heightened avalanche conditions on Wednesday, and the terrain at the Pass can turn even a small slide into a potentially dangerous accident. Steep, complex. and rocky terrain, especially where slopes are wind-loaded and/or unsupported are the most likely locations to trigger a slab. Safer conditions and excellent snow can be found on lower-angle runs outside of the wind zone.  

 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    On Tuesday, travelers in the Alpental Valley triggered multiple small soft slab avalanches and observed natural slab avalanches within Monday night's snow in wind-affected terrain, including one catch and carry. While we expect many of these slabs to stabilize by Wednesday, some could still prove reactive. On Wednesday, winds will increase and shift to the southeast, potentially forming new shallow wind slabs. It will be possible to trigger both older and freshly formed slabs on Wednesday, regardless of whether they are technically wind-loaded or not. 

    Slopes below steep ridgelines or cornices, entrances and sidewalls of gullies, confined chutes, rollovers, unsupported slopes, aprons below cliffs, and rocky outcroppings are all likely trigger points. If you see blowing snow, avoid any steep slope where it is landing, but that will only keep you away from the new slabs, not necessarily the old ones. Look for drifts, textured surfaces, and lens-like deposits, but keep in mind that much of the snow surface is only minimally wind-affected making it challenging to identify everywhere that could be harboring a potential soft slab. What's more, slabs in wind-sheltered terrain are less likely but not out of the question in isolated locations. Feel for dense over less dense snow, look for cracking in the snow surface, use hand pits, uptrack tests, and small test slopes to gauge slab behavior, and retreat to simple and lower-angle terrain if any of your assessments yield results. Most avalanches should be small, but carefully consider the consequences of a slide on the piece of terrain you are eyeing and choose simpler terrain with clean runouts to minimize the impact of a potential slide.   

    (3/18/2025)

    This 6" deep, soft slab avalanche was triggered by a skier on a steep rollover on a north-facing slope at 5100' on Tuesday. The skier was caught and carried, but fortunately not buried or harmed.

Avalanche Discussion

Another day brought another 7-8" fluffy snow to the Pass, with most precipitation finishing up by late Monday night. Most of the precipitation from the storm system inbound Wednesday should fall after the day ends, but if the flakes start to fly earlier or increasing wind blows around soft surface snow, danger could increase earlier in the day. Broadly speaking, the new snow is generally right-side-up, but has proven capable of producing small soft slab avalanches, especially in close proximity to the storm. The general pattern over the past week has been for an uptick in avalanche activity with each new load of snow, followed by a stabilizing trend, until the next round of precipitation. As far as we can tell, all triggered avalanches thus far have only involved the very recent storm snow, however, with so much recent snow, we can't fully rule out avalanches breaking into deeper snow layers.  

Let's step back and look at the bigger picture. It's spring (almost), and the weather is complex. Winds are blowing from all directions, sun and clouds bounce back and forth over the mountains, and potent storms continue to impact the zone. This dynamic weather creates a snowpack that is highly variable depending on elevation, aspect, and slope character, leading to differences in snowpack structure that are difficult to detect and even more challenging to predict their impact on the avalanche situation. One slope may be stable while another right next door may not. We have had at least 8 catch and carries with multiple partial burials over the past week in all of our zones. Thankfully, there haven't been any serious injuries, but that is beside the point. People, including multiple avalanche professionals, are getting surprised by and caught in avalanches. Most, but not all of these slides are breaking in quite steep terrain. Consider this before you step out into committing terrain and ask yourself, what will happen if I'm wrong?   

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