Avalanche forecast

Stevens Pass

Northwest Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

Storms have added 3-4 feet of snow in the past week. You can trigger avalanches in the recent snow especially where the wind has formed drifts at upper elevations, and you may even encounter dangerously deep avalanches on older weak layers.  Avoid being on or under large, steep slopes where avalanches can start or run at upper elevations.

Avalanche problems

  • Storm Slabs

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

    You're most likely to trigger avalanches in the recent layers of snow near the surface, or where the wind has formed deeper, stiff slabs. Avalanches in wind-drifted slabs could be large. You may still be able to trigger small avalanches lower elevations. If enough sun gets through the clouds, avalanches could become easy to trigger on southern aspects.

    Take time to test the new snow on inconsequential slopes before traveling in terrain steeper than 30 degrees. Stay off of and well out-from-under steep start zones in wind-loaded terrain, leeward sides of ridges, and all at upper elevations. With all the recent snow, be aware of falling in treewells and keep your partners in sight.

     

    (2/26/2024) An avalnache in East Highlands Bowl. Size D2. SE aspect 5600ft Photo: Jon Strahl

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–2.5

     These avalanches can be very dangerous and difficult to predict. The best way to manage them is to avoid avalanche terrain where the weak structure exists. Stay off of and far away from steep avalanche paths above 6,000ft. Avoid traveling in areas with complex, overlapping avalanche paths. Avalanches may propagate widely across terrain features, and run full path to lower elevations.

    The heavy snow and wind loading from the last week are stressing a weak snowpack structure. At and above 6,000ft, avalanches could break weak layers, including facets above the early February crust, 4-6 feet below the surface. The weak structure is weaker and more prevelant in the eastern portion of the zone. On Tuesday, avalanche workers triggered slides on this layer on shaded aspects. On Wednesday, skiers near Lake Wenatchee reported whumphing collapses on the same layer. Targeted snowpack tests (compression test, deep tap, propagation saw test) can help you identify the problematic layers. 

     

    (2/28/2024)

    In the neighboring East Central Zone. This remotely triggered avalanche in the Teanaway Drainage failed on facets over the Early February Crust. 

    5600ft, NEE aspectHS-ASr-R3-D2-O

    Photo: Mike Elges

Avalanche Discussion

As of Thursday evening, the Stevens Pass area has received almost 5" of water equivalent, and the snowpack has gained 3-4 feet since the 24th.

By Thursday morning another foot of snow had accumulated. Avalnches workers triggered mostly small avalanches in the recent snow, with one or two size D2. On Wednesday, avalanche workers triggered large and very large (up to D3) avalanches in the recent snow. On Tuesday, multiple observers reported sudden planar test results with compression tests on small faceted grains above the early February Crust. These came in from Grace Lakes and Lanham Lake areas on northerly aspects. Two significant (D2+) natural avalanches were observed from the Camp Chutes off the south side of Rock Mountain on Tuesday. The timing of these is unknown but estimated between the 26-27th. The slides ran down to the bottom of the track (gullies) at least. A wide slab avalanche occurred on a SE aspect at 5,600ft in Highlands Bowl on Monday, this was triggered by a smaller sluff. That same day control work at SPMR triggered a few avalanches that broke down to the early February Crust.

Riding conditions have been excellent, but with the incoming warming storm it'll be time to let the mountains ride out the storm. The very dangerous conditions are expected to last through the evening and natural avalanches may continue well into the overnight period on Wednesday. 

Submit observations here

Regions covered