Avalanche forecast

West Slopes Central

Northwest Avalanche Center
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Avalanche danger

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

Another round of snow and wind is in the forecast for Wednesday. You may find greater avalanche danger - and even a natural avalanche or two - during periods of heavy snowfall. Look for signs of wet avalanche activity at lower elevations with midday warming and a small rise in snow levels.

Avalanche problems

  • Storm Slabs

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

    Light snowfall overnight should increase during the day and join forces with strong winds and slightly warming temperatures. New snow amounts will likely vary across West Central. The greatest accumulation and danger will probably be in areas that see heavy, convergence zone-influenced snowfall.

    Human and naturally triggered avalanches will be more likely during the height of the storm. Take a big step back from avalanche terrain if you find more snow or witness more signs of instability (recent avalanches, shooting cracks) than anticipated.

    Wind loaded terrain will harbor thicker slabs, but all slopes with more than 6" inches of new snow should be considered suspect. You can stomp on small slopes or use other simple tests to evaluate the bond of new snow and wind slab layers. Stick to lower-angle slopes and avoid big terrain overhead if you want to keep things straightforward and easy.

     

    Shooting cracks are red flag signs of instability and should drive you to lower angled terrain.

    Photo: Robin Pendery

Avalanche Discussion

Non-avalanche hazards include frozen, partially buried avalanche debris, glide cracks, exposed creeks, and other natural hazards exposed by recent rain. Multiple observers out on Monday noted all of the above were greater dangers than triggering an avalanche - unless of course the avalanche pushed you into one of these traps. New snow will obviously change this equation but they will still be out there.

Tuesday was a quiet one across the Cascades with few people out in the mountains and even fewer observations. Mild and calm conditions are suspected of having little effect on avalanche danger other than giving dense, stubborn winds slabs even more time to bond and become unreactive. 

During the last storm on Jan 15-16th, West Central weather stations recorded 0.6-0.9” of snow water equivalent while White Chuck picked up 5” of new snow. Observations across the west slopes pointed towards a few different problems. Wet avalanche activity was the headline in Snoqualmie Pass with sun breaks warming the surface and triggering a round of small wet loose avalanches. One small natural slab avalanche was reported as well. Stevens Pass observers found similar but less widespread activity due to less sun and new snow. In West North (which received similar precipitation and snowfall as West Central) thick but mostly unreactive wind slabs were found down to and sometimes below treeline.

If you’re out and about, please send us some pictures of what you’re seeing by submitting an observation.

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