Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Mild weather should help lingering wind slabs heal and the avalanche danger to drop. You may still trigger a pocket of unstable wind-drifted snow near the tops of the higher peaks and where weak snow sits under the slabs. Be leery of firm pillow-like drifts, especially in rocky unsupported terrain.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Easterly winds built slabs in some unusual spots on Friday. Across the WA Cascades, this resulted in at least 10 unintentional avalanches in nearly every zone. Maybe it’s the strange loading patterns, or maybe it’s the underlying weak snow. Hard to say, but folks keep getting surprised. 

    At this point, most of these wind-loaded pockets will be hard to trigger. However, there could still be a few places where avalanches may occur. These would be most likely higher in the terrain, on unsupported slopes, and where facets underlie the slab. That last one’s the tricky spot. You likely can’t tell exactly where that is and is not. At least a few of these recent avalanches are suspected of failing on sugary facets. 

    Look for textured surfaces, scoured slopes, and drifts to point out potentially wind-loaded terrain. Well-supported and planar slopes help reduce the likelihood of triggering one of these old slabs. However, the only way to fully avoid them is to stick to lower-angled or sheltered areas.

    (2/16/2024)

    An unintentionally skier-triggered wind slab in a confined rocky chute. Note the textured surface up against the rock wall.

Avalanche Discussion

The weather and conditions seem to be stuck on repeat. Yet another weak system will bring precipitation on Monday. However, the southerly flow doesn’t favor the Pass, so any accumulations will be minor. Stronger easterly winds will probably create blustery conditions, especially in the morning. However, at this point, there just isn’t much soft snow left to move. You may see blowing snow or drifting, but it shouldn’t create any new hazards. 

Warmer air moved into the Pass on Sunday. This combined with mist to make some snow surfaces wet and sticky. Some rollerballs were reported, but no significant avalanches were observed. Sunday’s warm-up should limit any wet avalanche activity on Monday. A little rain, sun, or mild weather shouldn’t matter much. However, if you start to see rollerballs or find deeper, wet, punchy snow, be cautious of nearby steep slopes where small wet slides might occur. 

Most of the recent avalanche activity at the Pass was Friday when two human-triggered wind slabs occurred in the Slot and Snot Couloirs on the north side of Mt Snoqualmie. Other small natural wind slabs were observed on Saturday. 

The upper snowpack consists of around 18 inches of snow over the burly Early February Crust (EFC). Various layers of settled snow, facets, and crusts exist depending on aspect and elevation. Snowpack tests highlighted several potential weak layers, though they tend to be inconsistent. Many southerly and windward slopes have a crust at the surface, while soft snow often still lingers in shaded, sheltered terrain. 

Many travelers still report better-than-expected conditions. Elsewhere, breakable crusts, firm surfaces, frozen treebombs, and open creeks are the norm.

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