Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

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

Most of the avalanche danger remains confined to areas near ridges and cliffs where the wind drifted the snow into firmer and thicker slabs. Sharp cornices and sculpted snow can help you identify which wind-loaded slopes you want to avoid. Outside of these wind-affected areas, you will find lots of soft deep snow and maybe a few very small sluff avalanches.

Avalanche problems

  • Wind Slabs

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

    Windy conditions, particularly near the Cascade Crest Tuesday, formed a fresh new batch of wind slabs at mid and upper elevations. With so much low-density snow still available to blow around, even light wind speeds can continue to transport snow. While most wind slabs you encounter should be small and relatively easy to manage, some of these potential avalanches may grow large enough to bury you. Look for sharp cornices, drifts, and textured surfaces to figure out which areas could contain wind slabs that you want to avoid. 

    Cornices along ridgelines grew quickly during these recent storms. Several professionals remarked over the past few days at how easily these waves of snow failed. Be careful as you approach sharp ridges or anywhere you suspect a cornice might form. These features often break much farther back than expected. 

    (12/28/2021)

    Freshly built cornices were seen overhanging NE-E aspects of East Peak/Cement Basin on Tuesday 12/28. 

    Photo: Andy Harrington

Avalanche Discussion

It’s been a very snowy week in the West South zone with storm totals of 3-6 ft. Cooling temperatures throughout this period allowed this snow to bond well to the Solstice Crust and fall generally right-side-up. As a result, you will likely find plenty of soft, deep snow as you travel. On Wednesday, sunshine could cause the snow shedding from trees and rocks to trigger very small loose avalanches. We didn’t list loose dry avalanches as a problem, because most of these slides should remain confined to very steep and rocky slopes. However, don’t let these little sluffs catch you off guard if your plans take you into larger or higher consequence slopes. 

While we expect any avalanche activity to remain near or just below the surface, several larger avalanches from other zones have our attention. Very large avalanches were reported in wind-loaded terrain on Dec 26-27 on Shuksan Arm (West North), Mt Mastif (Stevens Pass), and Chair Peak (Snoqualmie Pass). While we haven’t heard of similar avalanche activity in the West South zone, the stormy weather this past week restricted travel and observations. These slides highlight the lingering potential for deeper avalanches in rocky and complex terrain at upper elevations. Take time to discuss this area of uncertainty in the snowpack before you commit to large rocky slopes. 

We expect a shift in the weather Thursday as temperatures warm slightly, winds increase, and more snow falls. This may increase the avalanche danger, particularly near the volcanoes. Several travelers reported weak snow (facets and surface hoar) at the surface in other zones. Now is the time to track these potential weak layers. As you travel Wednesday, make note of where you find sugary facets or feathery surface hoar and send us the observation. This data may help as we head into the next storm cycle.

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