Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

You'll need to manage both wet and dry avalanche problems on Friday. Avoid unsupported slopes, convex features, or wind-loaded terrain where triggering a slab is more likely. Wet avalanches are difficult to predict but could occur anywhere you sink into moist snow deeper than your ankle. 

Avalanche problems

  • Storm Slabs

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

    As you ascend in elevation, you'll encounter drier snow and the potential for slab avalanches. They'll be more likely on unsupported slopes, convex rollovers, or in wind-loaded terrain such as confined chutes or the base of cliffs. Slabs could be possible at elevations with moist snow but may be more stubborn. Use quick hand pits to look for potential layers of concern. Uptrack tests and small test slopes can help you gauge how the snow reacts to your weight as a traveler. Visual clues like large drifts, textured surfaces, or "fat pillows" can help you identify loaded features.  Avoid steep features over 35 degrees if you see any signs of instability.

    (3/27/2024)

    A skier triggered storm slab avalanche on a convex slope at mid-elevations. This occurred in the neighboring West South zone on Wednesday.

    Photo: Dallas Glass

  • Loose Wet

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

    Daytime warming, sun breaks, or rain showers could destabilize the snow surface and create the conditions for wet avalanches. Heavy wet snow already exists in many areas and is waiting for something to help push it downhill. Once these slides get moving, they can grow large and powerful as they descend and gather snow. In some areas, they could even trigger slabs. If the snow surface is wet and weak and you see new rollerballs, pinwheels, or snow shedding from trees and rocks, head for lower-angled terrain.

    In isolated locations, larger, more unpredictable shed-style avalanches could occur. Keep an eye on the terrain above you, and don't linger where you see precariously hanging blocks of snow.

    (3/27/2024) 

    Wet avalanche activity in the heavy, moist snow at lower elevations.

    Photo: Ryan Stoddard

Avalanche Discussion

Our warm but snowy week continued on Thursday. Springtime weather delivered another few inches of snow with wind to Snoqualmie Pass, with light rain at lower elevations. Alpental Pro Patrol reported 4-6" slabs during their morning mitigation work and wet loose avalanches at lower elevations as daytime warming destabilized the snowpack. A chunk of snow failed on one of their glide slopes, triggering a D1.5 wet loose avalanche on the slope below. Backcountry travelers have reported triggered slab avalanches in rocky chutes at upper elevations and wet slides at lower elevations. 

That pretty much sums up conditions at the Pass right now. Higher elevations are holding onto dry snow, while lower elevations are wet and punchy. There's a transition zone in the middle where you'll likely find a mix of the two problems and moist snow. Isolated larger avalanches could occur at any point as the mountains shed their winter coat. Expect similar conditions on Friday but with a higher chance for sun breaks and a downtrend in wind and precipitation amounts.

Roughly 1-2 feet below the surface, you'll find a crust from last week's warmup. We anticipate most avalanche activity to occur above this easily identifiable interface on Friday. Slides could fail within the wet and weak snow or the drier snow above it.

At lower elevations, our snowpack has taken a beating. You'll likely find punchy wet snow, patchy coverage, and exposed creeks/holes. Avalanche potential should be minimal, but you could see some rollerballs or small piles, especially at the upper end of the lower elevation band.

Regions covered