Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 3 years ago.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

Highlights

Thursday will give us a dose of everything: rain, snow, and sun. Wet avalanches will likely be the most widespread concern. However, you could still trigger an avalanche in pockets of wind-drifted snow at upper elevations. Steer around steep slopes with stiff wind-textured snow in alpine terrain, and consider shadier or lower-angle slopes if you're sinking deeply into wet, heavy snow. 

Avalanche problems

  • Loose Wet

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

    Thursday will be the warmest day yet this week. The snowpack surface has thin, superficial surface crusts, and another night of poor refreeze won't help reduce the wet avalanche potential as the day heats up on Thursday. Afternoon sunshine will also increase the likelihood of wet loose avalanche activity on sunny slopes. There isn't much fresh, dry snow out there, so we expect most avalanches to be small. But they could run naturally off steep rocks and cliffs, so be aware of the terrain above you. You could also trigger these slow-moving but heavy avalanches in steep terrain. If you begin to sink deeply into wet, sloppy snow, consider moving to lower-angle slopes or sticking to more northerly aspects. 

    (2/7/2024)

    Wet loose avalanche activity from steep cliffs warming in the sun. 

    Photo: Jonathan Spitzer

  • Wind Slabs

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

    In general, wind slabs are becoming stubborn and more difficult to trigger. However, since February 15th, there have been many recent close calls with people getting caught and carried in surprising avalanches throughout the Washington Cascades. It's been a few days since the last reported avalanche, but we need more confidence before putting this problem in the rearview mirror. Anytime we get this many reported avalanches, it usually means we are dealing with a tricky or unusual pattern. A couple of things could be factors in the prolonged instability of wind slabs and a higher-than-normal number of incidents. There is also weak, faceted snow associated with the Early February Crust. This weak layer is highly variable, making it nearly impossible to tell exactly where it exists in the terrain, and adjacent slopes could have very different stability. 

    Be suspicious of any firm slab in steep terrain at the uppermost elevations in the zone. These slides might be more likely in cliffy or rocky areas where the snowpack is often thinner and may be unsupported.

    (2/19/2024)

    This graph shows the general locations of recent natural and human triggered wind slab avalanches since 2/15. 

    Photo: Northwest Avalanche Center

Avalanche Discussion

It will be a mixed bag of weather on Thursday, with clouds and precipitation in the morning and sun breaks in the afternoon. Warm temperatures mean we'll see rain at the lower elevations but might get a few inches of snow up higher. On Wednesday, I was out in the Alpental Valley and found a moist but mostly supportable snowpack with a few inches of new snow. The upper snowpack has various crusts and weaker snow layers. None of these layers seemed particularly problematic, and the bond with the Early February Crust (EFC) down 3ft is improving. The once faceted, weak snow above this crust is rounding and gaining strength. A thin, zipper crust down around 2ft showed some signs of instability but was stubborn. Rollerballs were widespread, but no actual wet loose avalanches. The warm temperatures kept the surface crusts superficial, soft, and unsupportable to boots. The warm temperatures are helping to keep surfaces softer, but breakable crusts, frozen tree bombs, slick surfaces, holes, and open creeks are still common.

Regions covered