Avalanche forecast

West Slopes Central

Northwest Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

Avalanche activity is improving but you may still be able to trigger an avalanche in wind-drifted snow  on steep slopes. Steer around thicker, textured wind deposits, and avoid high consequence terrain where gullies, trees and cliffs are below you. Loose avalanches will continue to run- dry in the shade and wet as the sun warms slopes on the southern half of the compass. 

Avalanche problems

  • Wind Slabs

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

    Heavier snow deposits in wind slabs are where you are most likely to trigger an avalanche on Wednesday. Search for stiffer feeling drifts of snow, which may be fairly shallow and subtle at mid elevations, but stiffer and thicker as you gain elevation.  Avoid these wind-drifted areas on slopes steeper than 35°.

    You may be able to use smaller test slopes to see if you can trigger a small avalanche. Hand pits in the top foot or so of snow could be useful for identifying weaknesses beneath the slab. Start on small slopes before you go to big ones. If you do to travel into steep terrain, avoid slopes with terrain traps such as rocks, trees, cliffs, or gullies in the runouts, as these are areas you don't want to get carried into if you do trigger an avalanche. 

    Example photo: Wind slabs like this shallow one could fail on steep slopes with a human-trigger.

    Photo: Irene Henninger

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Loose snow avalanches, both wet and dry, will be abundant on Wednesday. When the sun shines intensely on a steep slope, expect wet loose avalanche activity to begin. A crust likely formed on suspect slopes from Tuesday, so the sun will have to cook through these frozen surfaces first. If you notice snow surfaces getting wet and heavy, and see any rollerballs or natural activity on steep, sunny slopes, avoid similar steep slopes and the lower-angle terrain beneath those steep areas. At first the sun will affect east-facing terrain, before it shifts southerly midday and around to the west near the end of the day. 

    You can trigger loose dry avalanches on steep, non wind-affected shady slopes at all elevations. On Tuesday backcountry riders reported loose dry avalanches carrying large amounts of mass. Expect the same on Wednesday. If you enter a steep slope be aware of the amount of loose snow running down with you. Don't let it catch you and take you for a ride. 

    (3/5/2024)

    Very small wet loose avalanche activity in the neighboring West North zone. Note how these avalanches naturally occur around rocks (and trees) before other nearby spots. 

Avalanche Discussion

The Skookum weather station in the southern half of the zone received 11 inches of water in the large storm cycle which has just concluded. The snowpack went from 20 inches to 54 inches. White Chuck almost doubled, going from 74 inches to 132 inches.  Most of the new snow has been found to be fairly "right side up" and stable, with shallower storm snow instabilities mainly stabilizing by now. The low-density snow we've received in the last few days has settled at the rate of several inches a day on total snow stakes. This light, fluffy surface snow is still a serious concern for snow immersion suffocation

Beneath the deep new snow layer, there have been very large avalanches reported in neighboring zones. In the neighboring West North zone, which has a snowpack most similar to the West Central zone right now, the avalanches were mainly during last week's High danger period. Avalanches likely failed on weak layers either above the Early February Crust or above the 2/24 crust, which are about 1ft apart. It's very unlikely that a human can trigger an avalanche on this layer, which is probably 6-12 feet or so beneath the surface in most areas. A huge cornice fall would be the most likely culprit for a resulting very large avalanche.  If the weak layer is anywhere, it is probably on north-facing upper-elevation slopes. Nearby zones, with much shallower snowpacks, are seeing human-triggered avalanches on this layer still, like THIS one reported at Stevens Pass on Tuesday.  

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