Avalanche forecast

Stevens Pass

Northwest Avalanche Center
View on map

Avalanche danger

Thu
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
Open full map
Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Very large and destructive wet avalanches may spontaneously occur with continued rain and warm temperatures on Wednesday. These slides are running 3-4ft deep and are powerful enough to take out trees. Although the danger isn't rated High, it's a good day to stay off of and well away from steep slopes. 

Avalanche problems

  • Glide Cracks

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

    Heavy rain should start running through and underneath the snowpack. Glide (slipping of the entire snowpack) activity has increased over the past 24 hours, and may pick up on Wednesday. Typically glide slabs run on smooth bedsurfaces, like rocks and grass. Large, complex terrain features can funnel slides into gullies. Stay away from these runout zones while its raining or if you see glide cracks. 

    (1/30/2024)

    A glide avalanche in Snoqualmie zone. This frequent flier is a good indicator that water is still making its way through the snowpack. We're not done with wet avalanches.

    [E 3900' WS-N-R2-D2-G]

    Photo: Alpental Pro Patrol

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–3

    A prolonged period of warm and wet weather, combined with a deeply buried weak layer have created unique conditions for scary and deep wet slab avalanches. These are running on old faceted and crust layers from December. What does this mean? It means slides may fracture widely across terrain features, and carry most of the seasons snowpack with it. Slides may be 3-4ft deep, and could be powerful enough to take out trees. 

    The easiest solution will be to skip travel on or under steep slopes until the snowpack has a chance to stabilize and temperatures trend more seasonal. Even if avoiding travel on steep slopes, the best policy would be to also pay close attention to what is above you.  Stay out from under cornices that could fall and trigger a large avalanche on the slope below.

    (1/30/2024)

    Very large wet slab debris took some trees out at SPMR.

    Photo: SPMR

Avalanche Discussion

The final punch of rain with warm temperatures is incoming on Wednesday. With the prolonged warm temperatures and rain, water has been slowly percolating through the snowpack. Snow is beginning to sag away from rocks and cliffs, and glide cracks are opening up. The Snow Safety department at Stevens Pass Mountain Resort was busy on Tuesday doing explosive testing much of the day. They reported a handful of very large avalanches with control work, and at least one D3 that took out trees. Slides stepped down to old weak layers, and one path even slid twice (the bedsurface of a slide triggered earlier in the day ran). A very large natural avalanche (D3) was observed in the Chiwaukum Range, along with a number of D2's. The larger slide appeared to have taken out trees. The trees and the bedsurface sliding stick out to me, and say its uniquely dangerous out there. Not a great day for travel in or around avalanche terrain!

An initial period of avalanche activity seemed to happen at the end of last week and over the weekend.  Many wet loose and slab avalanches up to D2 were reported. Avalanche control work at Stevens Pass Ski Area over the weekend produced a couple of avalanches that broke into older, deeper layers that have been lingering in the snowpack since late December. Regionally, very large slides have occurred on a similar old weak layer at Mission Ridge on Wednesday and Crystal Mountain a week ago. This crust/facet complex is now 3-4 feet below the surface in much of the zone. Last week, observers reported sudden and propagating test results on this weak layer.

If you make it out, please share what you found with an observation.

Regions covered