Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

Recent avalanche activity in wind-loaded terrain is bullseye information that dangerous avalanche conditions exist at upper elevations. An unfavorable bond at the base of the recent storm snow to a firm crust means that these slides could be easy to trigger. Don't get lulled to sleep by benign conditions down low, as you ascend the danger increases rapidly.

Avalanche problems

  • Wind Slabs

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

    Lots of people out there triggering avalanches in wind-loaded terrain on Saturday, including gullies, chutes, the base of cliffs, and rocky terrain. Add in leeward ridgelines, convex features, and unsupported slopes and you've got a list of known features to avoid so that you don't trigger one yourself on Sunday. Slabs will be more likely as you ascend toward wind-exposed elevations with higher storm totals. Use small slopes where you're not in danger of being caught in an avalanche to test the storm snow to see how it reacts to your weight. Use numerous quick hand pits as you travel to check the bond at the 1/10 interface. It will likely change as you ascend and move through the terrain.

    (1/11/2025)

    A human-triggered wind slab in a confined gully. Near a ridgeline. At the base of rocks. All classic locations for you to look for wind slab development.

Avalanche Discussion

Saturday morning, a group of four backcountry tourers were involved in an avalanche accident near Kendall Peak in the Commonwealth Basin area of Snoqualmie Pass. Details are still being gathered, but the accident occurred on a SW aspect at 5600ft. All four members were caught and carried. Two were injured. The party called 911 to request assistance. Search and rescue responded to the area and brought the victims to the trailhead.

Luckily there were no fatalities on Saturday, but apparently, people weren't heeding the advice that dangerous conditions existed at upper elevations. Numerous observations have come in of human-triggered avalanches and shooting cracks, almost exclusively in wind-effected terrain. The best sign of avalanche potential is recent avalanches, so these observations speak for themselves and are driving the Considerable rating at upper elevations.

Apart from avoiding wind-loaded features, you need to continue to focus your assessments on the 1/10 interface at the base of the storm snow. At lower elevations, you may find a subtle interstorm crust from the warm-up on Friday, but you're looking for a stouter crust deeper down. As you ascend in elevation, you'll find that the subtle layer disappears and there will be no question as to where the base of the storm snow is. Weak snow such as surface hoar and near surface facets existed on top of this crust before the storm and could result in surprising avalanches, even in wind-sheltered terrain. Observations from Saturday indicate that the bond at the 1/10 interface is poor to moderate, at best. Hand shears were all reported to have been mostly planar, with a range from failing on isolation to being stubborn/resistant.

As the sun comes out and temps rise over the next few days, take note of how the snow surface is changing. You may see rollerballs, pinwheels, or new avalanches develop such as loose. This process could start on Sunday.

Before this storm, travel conditions were very challenging due to breakable crust, icy slopes, frozen tree bombs, and piles of avalanche debris. The new snow has helped, but many of these hazards are now only a few inches below the surface, making them more difficult to spot.

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