Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
View on map

Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
Open full map
Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Cool temperatures and mostly cloudy skies should help limit the avalanche hazard on Monday. However, a few firm wind-loaded pockets may still linger higher in the terrain especially in rock-walled chutes and near the base of cliffs. Steer around smooth pillow-like drifts to avoid this problem.

Avalanche problems

  • Wind Slabs

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

    Friday and Saturday backcountry travelers triggered avalanches and reported unstable snow in rock-walled chutes in the Snoqualmie backcountry. While these older wind slabs are becoming harder to trigger, if you’re going to find one, it will likely be in this exact type of terrain. Look for sharp cornices, drifts, and firm pillow-like slabs near the entrances to chutes or along the base of cliffs. Some of these slabs are hard and could break above you. This can make them very difficult to manage. If you suspect wind-loading in these high-consequence features, seek out more sheltered terrain. 

    Strengthening easterly winds on Monday could begin to drift snow into fresh thin slabs at mid and upper elevations. These new wind slabs should be relatively small and harmless. Don’t let them catch you off guard and knock you off your feet. 

    (12/30/2022)

    This wind slab avalanche was skier triggered in the Guye Peak Couloir Friday. 

    Photo: Public Observation

Avalanche Discussion

Monday’s weather should help the snowpack gain strength and limit the avalanche danger to higher elevations wind-loaded areas. Other locations should experience generally safe conditions, However, the line between safety and hazard in a forecast can be very thin. If more sun occurs than expected or if stronger winds move more snow, you could see increasing danger. Pay attention to the weather and compare it to what you expected. If it deviates, you may encounter additional loose wet or more widespread winds slab issues. 

On Sunday, clear skies allowed the sun to moisten steep southerly slopes. While small loose wet avalanches were reported, most observations indicated piles of rollerballs. As temperatures dip, this will likely form a new crust in these same areas. In locations not receiving direct sunshine, cold dry snow remains. 

Most information from the Pass indicates 12-18 in (30-45cm) of cold dry settled snow sits over the Christmas Crust at mid and upper elevations. Lower in the terrain wet heavy snow and rain this week created variable snow surfaces and depths. While some inter-storm layers have been reported, we have not heard of any avalanches on these layers this week. Recent activity has been limited to wind-affected terrain and natural loose wet slides.

Regions covered