Avalanche forecast

Stevens Pass

Northwest Avalanche Center
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Avalanche danger

Fri
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

After a very active and stormy day, it will still be easy to trigger avalanches in the recent snow, especially where winds drift fresh slabs of snow. Use quick tests and small test slopes to check how easily the snow slides before committing to bigger pieces of terrain. 

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1.5–2.5

    You may still be able to trigger avalanches 1-2 feet deep on steep, wind-sheltered slopes. At mid to upper elevations, avalanches will be easy to trigger on steep, leeward slopes. On Thursday,  new slabs will be drifted on specific peaks and features nearest to the Highway 2 corridor that are exposed to east wind. Watch for wind transport and cracks shooting through the snow as indicators of the danger. Fresh drifts and any features over 35 degrees. 

    3-5ft thick slabs of recent storm snow are resting on crusts and weaker layers buried in late December. Several wide and deeper avalanches occurred around the 11th. The new load could be enough to re-activate these deeper weak layers. These very large avalanches could run full path and would be difficult to survive. It would be wise to stay away from large runout zones until we know more about Wednesday's avalanche cycle. 

    (1/17/2024)

    A small skier triggered, storm slab avalanche. 5250ft, NW, Stevens Pass sidecountry

    Photo: Josh Hirshberg

Avalanche Discussion

Stevens Pass picked up nearly a foot and a half of new snow by the end of Wednesday.  Snowfall rates were very heavy in the middle of the day. Observers reported numerous triggered and natural avalanches in the new snow. While instabilities in the new snow in immediate terrain were obvious, visibility was poor and we really don't know what happened in larger pieces of terrain. During the last storm, on the 11th, some very large avalanches ran on deeper weak layers. 

In general, the recent cold temperatures have promoted faceting of snow surfaces on all aspects; sometimes, these weaker grains are lying on a crust. The variety of old surfaces includes thin crusts from the sun, zipper crusts from earlier in January, old wind board or soft wind-etched snow, and faceted grains and/or surface hoar on sheltered shaded slopes.  

Region-wide there are old crust and facet weak layers that have persisted, and may become active once again with more snow. Between the 6th and the 11th, several very large and deep avalanches have been observed in the Cascades. A couple examples of these are the 6ft deep slab at SPMR with control work on the 10th and a very large (D3) avalanche on the NE side of Jove (estimated to have occurred on the 11th). The layer responsible for these larger slides is likely the Solstice crust, which is now about 4 feet below the surface in much of the zone. Snow profiles have shown these weak layers to consist of faceted melt forms, and some snowpack tests have given sudden and propagating results. These layers have gone dormant recently, but this storm could be enough of a load to begin seeing more activity on it.  This feeds into uncertainty with travel. The best advice is to let this storm play out, and stay away from large, steep features where full-path avalanches could run. 

Further east there is a similar but shallower snowpack structure. Here, persistent slabs are trending less likely, but remain on the menu. 

Regions covered