Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Fri
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Out of date — this forecast expired 3 years ago.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

You can trigger an avalanche in lingering pockets of wind drifted snow on Thursday. Consider steering around wind loaded features if you notice active drifting or see signs of unstable snow such as shooting cracks.

Avalanche problems

  • Wind Slabs

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

    Strong, sustained east winds have been ripping across the Cascades. This wind pattern is likely creating variable surfaces, but also forming slabs in some funky spots, such as west aspects or even cross loading terrain features at higher elevations. Thursday will bring a switch back to westerly winds, which may start blowing snow back onto more normal east facing slopes. 

    So as you travel, don’t let your guard down as you switch aspects. Keep an eye out for these shallow wind drifted slabs all over the compass. You use visual clues to help you identify slopes of concern. Look for blowing snow, textured surfaces, or fresh rounded pillows at the snow surface to help you identify where the problem exists. As always, take a step back and reduce your exposure to steep wind loaded slopes if you notice signs such as shooting cracks or hear snow that sounds hollow like a drum.

    (3/6/2023)

    Pump the brakes and avoid steep, wind loaded terrain if you notice shooting cracks in drifted snow like this. 

    Photo: Joe Dellaporta

Avalanche Discussion

Thursday should bring more of the same, just with a changing wind direction and possibly some filtering sunshine to start the day. Although, clouds are forecast to thicken as the day progresses, along with increasing ridgeline winds ahead of our next system. 

Strong, sustained east winds have likely done some damage at upper elevations. On Wednesday, winds finally started easing as temperatures warmed up above freezing at the top of Alpental. This combination has likely created variable travel on most aspects and elevations below 5500’. 

Last week's snowfall overlays a melt-freeze crust on most aspects except high-elevation northerly slopes (3/22 interface). Multiple shallow (3-10") soft slab avalanches were human-triggered over the weekend, failing within or at the base of the recent storm snow. Most of these slides appeared to be on steep convex slopes or near rocky terrain, such as rocky chutes or the base of cliffs. Avalanche professionals and NWAC forecasters identified pockets of weak snow, with a few whumpfing collapses experienced on west aspects at mid to upper elevations. 

We had some concerns about weak snow buried during this storm. If it survived, the distribution is spotty at best, but it could explain some of the collapses or a few of the triggered slabs. We are continuing to gather more information about this potential weak layer in the snowpack. So be sure to check the bond on the 3/22 interface and the snow above it as you travel on Monday. We expect any avalanche activity to occur at or above this interface.

Regions covered