Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Wednesday should be a blustery day in the West South zone with yet another wind direction change. Keep an eye out for wind-loaded pockets on a variety of aspects as you ascend in elevation. Actively blowing snow and fresh cornices can help you identify the terrain features you should steer around.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Easterly winds should increase throughout the day, growing strong enough to easily move snow. The question then becomes, how much snow is available for transport? At upper elevations, we believe there’s enough that you could encounter some freshly built Wind Slabs on specific terrain features such as in confined gullies or near ridgelines. With east wind events, there is often more cross-loading or mid-slope loading than with our typical storm patterns. So take a good look for visual clues like actively blowing snow, fresh drifts, or new cornices to help you identify wind-loaded pockets to avoid, they may be on aspects or features you’re not used to.

    (1/2/2023)

    A small human triggered winds slab in the Crystal Backcountry, 1-2ft deep and 40ft wide. W, 6300ft, HS-AS-D1-R2-U 

    Photo: Barrett Gray

Avalanche Discussion

The wind direction has flip-flopped multiple times in the past few days, and on Wednesday we’ll flip back to more easterly. We’ll likely encounter some of the windiest conditions we’ve seen in the last week in the West South zone, particularly in areas closer to the crest. In those same areas, we could even squeeze out an inch of snow to help in developing new shallow Wind Slabs.

Over the New Year’s weekend, multiple human-triggered avalanches were triggered in wind-loaded terrain throughout the zone. In some instances, hard slabs were reported, which jives with observations from Crystal, White Pass, and Mount Rainier National Park. Hard slabs can make predicting where and how a Wind Slab fails difficult. These slabs should be trending toward unlikely at this point, but that doesn’t mean they’re completely finished, especially with some additional loading. 

In more sheltered areas, you should find generally safe avalanche conditions and a well-settled snowpack over the Christmas Crust. Widespread surface hoar has been reported in these areas and could produce a few surprising avalanches if it’s not wiped out by the wind and a shallow slab forms above it. On slopes that see direct sunshine, you’ll likely find that a slick sun crust developed on New Year's Day and you may see some evidence of recent Wet Loose activity such as old rollerballs. We do not currently have any concerns below the Christmas Crust that should be on your radar.

Regions covered