Avalanche forecast

West Slopes Central

Northwest Avalanche Center
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Avalanche danger

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

Identify and avoid pockets of recently wind drifted snow as strengthening afternoon winds ramp up ahead of a storm. Avalanche danger will be highest at the end of the day. Anticipate a stormy weekend with heavy precipitation and rising snow levels.

Avalanche problems

  • Wind Slabs

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

    There is just enough snow and wind in the forecast that wind slabs should be on your radar. There might not be a ton of snow available for transport at mid-elevations. It could be a different story as you head up to higher elevations where more snow available for transport means bigger, thicker slabs that might also be easier to trigger. 

    If the wind is blowing, drifting snow will show you which slopes are loading up. Track changes in snow texture, stiffness, and depth to hunt down fresh slabs if you find calmer conditions. Simple tests like hand shears and small slope cuts can show the bond of wind slabs to the layers below. When in doubt, just avoid slopes holding recently wind drifted snow to reduce the likelihood of triggering an avalanche.

    Drifting snow and cornices are easy clues to figure out where wind slabs are forming.

    Photo: Joe Dellaporta

Avalanche Discussion

Both Friday and Saturday are shaping up as transition days ahead of the warm and wet storm bearing down on us for the weekend. An NWAC Forecaster in Stevens Pass found generally stable conditions. Previous wet avalanche activity was noted, but clouds kept warming at bay for most of the day. Moderate winds transported snow at ridgeline, but minimal new wind slab development was noted. More signs of wind effect were seen in more exposed, upper-elevation terrain. Recent storm interfaces were observed to be gaining strength. The weak snow at the January Drought Layer is rounding and showing minimal reactivity in testing.

The widespread wind slab instability found Wednesday in West North had started to resolve by Thursday as reports indicated a strengthening bond at the wind slab/crust interface. One team did trigger a slab avalanche on a very steep, previously wind-loaded gully wall. The person who triggered the slide was caught and partially buried, but no injuries were reported. It's unclear if this slab failed at the wind slab/crust interface or in a slightly deeper layer. No other new avalanches were reported.

A number of large natural avalanches were also observed, all of which likely occurred during the peak of snowfall and strong winds. Some featured very wide propagation. It's uncertain exactly at which interface these avalanches failed. 

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