Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

Fri
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Get ready for a series of storms starting overnight Wednesday and lasting into the weekend. Heavy snowfall and strong winds will sharply increase the likelihood of triggering or being caught in an avalanche. Choose conservative terrain while the storms play out.

   

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5

    West North should see 1-2’ of new snow, and stormy conditions may last into Thursday morning. New snow layers often bond quickly and show an increase in stability as the storm ends and the day goes on. But increasing winds ahead of the next storm could build another round of slabs and keep dangerous avalanche conditions in play till day's end.

    You are more likely to trigger a slab on wind loaded slopes, but there should be enough new snow that it would be wise to look for instability in sheltered areas as well. On-the-fly stability tests like hand shears and test slopes should show the bond of new snow layers. When in doubt, stick to simple, lower-angle terrain.

    (12/31/2022)

    You are definitely more likely to trigger any type of slab avalanche on a steep, unsupported slope.

    Photo: Zack McGill - Cascade Mountain Ascents

Avalanche Discussion

Observations were a bit sparse on Wednesday. Those who were out reported wind scoured ridgelines and fresh wind slab formation on leeward slopes. Less significant wind transport was observed in lower-elevation areas. Avalanche observations consisted of a few naturally triggered wind slabs on steep slopes below corniced ridgelines. With fresh wind slab formation, sings of instability and deteriorating visibility, most stuck to smaller terrain as the day went on.

Stability tests have shown weaker layers in the upper snowpack as gaining strength and becoming more resistant. The facet or facet-crust layers - one down 16-24” and the other 36-48” - produced minimal avalanche activity in the last week, with one reported avalanche suspected as failing at one of the layers in question. A much bigger load in the next 72 hours should give any lingering weakness one final test and possibly produce some very large avalanches in the stormy period ahead.

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