Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
View on map

Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
1 · Low
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Out of date — this forecast expired 3 years ago.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

The winds are shifting back easterly and will be accompanied by a trace of new snow. Wind slabs could exist on various aspects at upper elevations due to the shifting wind direction this week. Take a peek at the upper snowpack for a slab over weak crusts if you’re traveling in consequential terrain.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    East winds capable of creating fresh wind slabs will return to the Snoqualmie Pass zone on Friday. The question becomes, how much snow is available for transport? There may be enough dry snow at the highest elevations to form shallow wind slabs on leeward slopes. Look for them near ridgelines, the base of cliffs, or in confined chutes/gullies. Due to the atypical wind direction, they may form on aspects where you’re not used to seeing them. Actively blowing snow, fresh cornices, or drifts behind objects can help you identify their locations.

    (12/27/2023)

    Visual clues such as drifts behind objects and textured surfaces can help you identify which direction the wind was blowing.

    Photo: Josh Lipkowitz

Avalanche Discussion

Snow height around the zone increases dramatically at the Pass proper and as you ascend through the middle elevation band. The upper snowpack consists of a series of crusts and dry snow, while the lower snowpack is strong and compact. Two of these crusts, the 12/22 and the 12/25 interfaces, have the characteristics of layers that could give us trouble in the future if we receive a significant load. You may want to examine these layers before jumping into consequential terrain. 

On Thursday, avalanche professionals in the Alpental Valley reported wind drifts that were stubborn due to the warm moisture that has seeped into our snowpack. They could be more reactive if you are traveling into extreme or high alpine terrain. 

We’re in a persistent pattern this week of shifting winds and light precipitation- either snow, drizzle, or freezing rain, depending on elevation. This will continue on Friday as the east winds kick back up. They shouldn’t be as strong as they were on Wednesday. They are expected to be powerful enough to move snow around and coat trees, rocks, and infrastructure with rime or freezing rain.

During your travels, you’ll likely encounter slopes that are stripped down to a frozen crust, pockets of wind-drifted snow, and areas of moist snow capable of producing rollerballs and small wet avalanches. Despite the less-than-ideal snow coverage, backcountry travelers have started to push into terrain this week that many have avoided. With careful and thoughtful travel, you can have a nice day out in the mountains by avoiding the open creeks, exposed rocks, and sometimes firm snow surfaces. We want to hear about those days out, so submit an observation and let us know what you're up to. 

Regions covered