Avalanche forecast

East Slopes Central

Northwest Avalanche Center
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Avalanche danger

Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Strong winds drifted recent snow into stiff slabs where you can trigger avalanches. Higher elevations near ridges, steep mid-slope rolls, and the base of cliffs are likely spots to find these slabs. Steer around steep slopes with "fat" looking drifts or stick to wind-sheltered areas. If traveling near Stevens Pass, avalanches may be larger and potentially step down to deeper weak layers.

Avalanche problems

  • Wind Slabs

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

    Strong westerly ridgeline winds are drifting recent snow into reactive wind slabs, particularly at upper elevations and areas near the Cascade Crest with higher storm snow totals. The most likely locations to trigger avalanches will be on steep slopes below ridges or mid-slope features such as convex rolls, which are common trigger points. With wind speeds up to 30mph, you may find wind slabs lower down on the slope than you would typically expect. There is a possibility that wind slabs could step down into deeper buried weak layers. This scenario would produce a much larger, surprising avalanche that could be unsurvivable. This problem is particularly concerning in areas near and around Stevens Pass. Although uncertainty exists, similar conditions could also linger in areas further east. With this increased uncertainty, travel with a conservative mindset and consider wider safety margins.Look for signs of wind slab formation, such as actively drifting snow and textured surfaces. You can also use your probe or pole to feel for stiffer snow over softer snow layers. Cracks that shoot away from your feet or equipment are a sure sign of unstable wind slabs. If you observe these long cracks, use lower-angle routes or move to sheltered terrain. 

    (2/9/2023)

    An intentionally triggered wind slab on a leeward slope from Feburary 9th after a significant storm. 

    Photo: Matt Primomo

Avalanche Discussion

In favored areas near the Cascade Crest, 6-8 inches of snow accumulated along with strong winds throughout the day on Monday. Places further east did not quite get as much snow but were also not spared the strong winds. Wind speeds at Mission Ridge and Dirtyface Mt were between 20-30mph for most of the day, with some hours recording sustained winds over 40mph. Precipitation will taper off, but winds will continue into the morning hours on Tuesday. 

On Sunday, observers reported moist snow surfaces up to 7000 ft. Warm temperatures dropped below freezing, and with the lack of new snow, these wet snow surfaces are refrozen and present challenging travel conditions. So anticipate slippery melt-freeze crusts and refrozen "chunder" under the forest canopy. 

In the nearby Stevens Pass zone, there have been large avalanches with wide propagation, potentially on buried weak layers resting over stout crusts. On Saturday, a report came in of a rider triggering a slab avalanche on an ENE aspect at 5400 ft (observation). Another observation came in on Sunday evening of a widely propagating avalanche on the south aspect of Jove Peak ( observation here). While we are uncertain of the failure layers of these avalanches, it doesn't change how we treat this difficult persistent slab avalanche problem. We have not yet confirmed any avalanches on these layers in East Central, but we have been tracking weak snow over the MLK crust for some time now. On Saturday, NWAC forecaster Joe Dellaporta observed a propagating snowpack test result on this layer buried around 17 inches deep on Dirtyface Mountain. The difference between Stevens and East Central may simply be that there is less slab over these layers in East Central, and it could become a problem with additional snow load. These avalanche occurrences are worth noting if you plan on traveling along the western edges of the East-Central and considering the consequences of triggering a larger and more surprising avalanche.  

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