Avalanche forecast

West Slopes Central

Northwest Avalanche Center
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Avalanche danger

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

 

Both new and older slabs of wind drifted snow can be found on most aspects near and above treeline. Bypass steep slopes where you identify wind drifted snow to reduce the risk of triggering an avalanche. Be prepared for very cold temperatures on Wednesday.

Avalanche problems

  • Wind Slabs

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

    Differing vintages of wind slab can be found on just about every aspect in wind exposed terrain. Observers on Tuesday in both West North and Stevens Pass reported easterly winds drifting snow onto leeward slopes. Though greater wind transport was observed in alpine terrain there was also enough transport near treeline to build scattered wind slabs.  

    Older wind slabs from Saturday’s storm still exist on north and east aspects but became much less reactive to human triggers in the last two days.

    You will need to track the wind loading pattern in the surrounding terrain as you travel. Scoured snow surfaces, slabby-looking drifts, cornice features, changes in snow texture - pay attention to these and other clues to identify where both old and new wind slabs lurk. Use simple tests in safe areas to see how well these slabs are bonded to layers below - or simply bypass steep wind loaded features on lower angle, planar terrain

    (2/20/2022) Skier triggered slab avalanche on Huntoon Point in the Baker backcountry. This was an obviously wind-loaded rocky outcropping. Approximately 18" deep, 150ft wid. N, 5100ft.

    Photo: Pete Durr, USFS Backcountry Ranger 

Avalanche Discussion

Saturday’s storm put down 2-4” of precipitation across West Central with up to 3' of new snow in locations favored by the convergence zone. Human triggered wind and storm slab avalanches to D1.5 were reported in West North around the Baker Backcountry (Artist Point, Table Mt.), Schriebers Meadow/Mt. Baker NRA and Canyon Creek over the holiday weekend. Small loose snow avalanches, natural and human triggered, were also observed on Sunday and Monday. They occurred on both shaded and sun exposed slopes. Very cold temperatures on Wednesday should keep loose wet avalanches in check though small loose dry avalanches should still be a consideration in very steep, shaded terrain.

Observers in the Mountain Loop Monday found 2' of right-side-up new snow above a weak crust buried on February 19th. They also found they found 0.5mm facets between this crust and the February 14th/Valentine's crust just below, This weak layer produced sudden results with Compression Tests and propagation with Extended Column Tests. Deeper crust-facet layering from late January can still be found in shaded, alpine terrain but no new natural or human triggered avalanches associated with these layers have been reported in the last week.

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