Avalanche forecast

East Slopes Central

Northwest Avalanche Center
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Avalanche danger

Sun
Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
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Highlights

Triggering a slab avalanche has become unlikely, but still use caution near upper elevation wind-loaded pockets. In these areas, you could still encounter isolated pockets of unstable snow. Avoid larger slopes if you notice shooting cracks or hear audible collapses. 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1–1.5

    Recent warm temperatures and time are helping these wind slabs gain strength. However, at upper elevations, you'll still encounter dry snow available for transport and may even notice moderate wind speeds drifting snow. With this, you may still encounter pockets of unstable snow in wind drifted areas. 

    These unstable slabs will be most common on the leeward sides of ridges, below cornices, near the tops of chutes and couloirs, and scattered throughout the alpine. All that said, recent east winds may throw you a curveball, so look for these slabs in some not-so-common areas, like across terrain features (cross-loading) or even on west aspects. 

    Pay attention to the direction of wind loading and use visual surface clues to help you identify the avalanche problem. Look for sharp drifts, pillow-like slabs, or dunes at the snow surface to help you spot where the wind has been at work. These slabs could break in surprising ways if they rest on surface hoar, facets, or recently buried crusts. Use small test slopes or hand pits to gauge how reactive the slab is. Consider steering around steep wind-loaded slopes if you notice active drifting or signs of instability, such as shooting cracks or hear whumphs. 

    (12/1/2023)

    Use small test slopes and look for signs of instability like this before committing to steeper slopes.

    Photo: Joe Dellaporta

Avalanche Discussion

Saturday's system could be more exciting for the eastern cascades. You'll likely just encounter light mixed precipitation and fortunately, some decreasing wind speeds. Elevations below 6000 ft have been warming above freezing in the past two days so you may encounter variable travel and a crust on solar aspects. 

Our most notable observation on Friday was from a backcountry traveler in the Stuart Range who experienced a large collapse at 4600' and found consistent failures on a crust layer in the upper snowpack. Another observer in the Blewett Pass area observed a weak snowpack structure and propagating test results in wind-loaded pockets on the 12/19 crust-facet layer. This layer sat 9-12 inches below the snow surface in this location. Thursday, NWAC observers found a similar weak structure in the Dirtyface and Holden areas but observed minimal signs of instability while traveling. Check out their observations from Holden and Dirtyface here and here. 

All of this information clearly illustrates a poor structure. We have a lot of uncertainty at upper elevations across the zone. So keep this information at the forefront of your mind in those locations that could have a slab resting on this setup, like upper elevation wind-loaded areas potentially. But by and large, we're still waiting on one more key ingredient in most of the zone - more of a slab. Stay tuned. 

If you get out, let us know what you see by submitting a public observation.

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