Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Wet avalanche activity is your main concern as we rapidly transition to spring this weekend. It won't take very long for wet snow to start sliding once the sun cooks steep slopes on the southerly half of the compass. Shift off steep sunny slopes and terrain beneath them when snow starts getting wet and mushy, or if you see any avalanche activity. 

Avalanche problems

  • Loose Wet

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

    Snow will quickly get wet on steep east-facing slopes in the morning, shifting more southerly midday, and then west-facing slopes in the afternoon. Expect more shedding off rocks and near trees. Make a plan to avoid steep slopes and terrain beneath them once the intense sun starts cooking them. Shift to lower-angle terrain, away from higher angle overhead hazards or to shadier aspects.  

    Wet avalanche activity kicked off in some areas of the zone on Friday, yet some locations still may have cold dry snow. The initial wetting of cold, dry snow is when you can expect to see the most avalanche activity. We expect wet activity to continue as temperatures are warmer and more sunlight is expected on Saturday, although it may not be as active as the initial day of wetting.

    (3/29/2024)

    Fresh wet loose covers the debris from a much older glide avalanche that initiated from a rock slab. East aspect of Anderson Butte at 5000'

  • Wind Slabs

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

    Subtle shallow wind slabs may still react to a human trigger, predominantly at upper elevations. Slabs that just start to get moist may avalanche with a human trigger as well. These deposits of heavier snow will likely remain small, but even a small slide could still cause harm or kill you if you're in exposed high-consequence terrain, like areas above cliffs or rocks, trees and gullies.

    Search for wind-textured surfaces, or slightly stiffer feeling snow. This may be a very slight difference from non wind-affected snow. In the last few days the slab activity we've seen has been in small gullies and tight features rather than on broad slopes. Any weaknesses are probably shallow, so you can use your hand to dig down and see if there are any failure planes in the new snow layers. Consider steering around wind slabs on exposed terrain greater than 35°. You probably won't see any slab avalanche activity in areas where there's a crust on the surface. 

    (3/29/2024)

    Human triggered slab avalanche in the Baker backcountry. N, 5000ft. D1.5

    Photo: Zack McGill - Cascade Mtn Ascents

Avalanche Discussion

Reports came in from many areas of the zone on Friday. Each location had very different conditions: Greenhousing was caused by low clouds, resulting in moistening and wet loose avalanche activity on all aspects at Anderson-Watson Sno Park up to well over 5500ft (observation). A thick layer of graupel and stormy conditions for most of the day was the case at Canyon Creek, and a few small slab avalanches were triggered. The Baker backcountry was reported as "hot," and wet loose avalanche activity resulted on steep, sunny slopes. One small human-triggered slab avalanche occurred. 

Considering the variable weather and snow conditions on Friday, different areas in the zone will act differently on Saturday. Some slopes will be seeing their first round of warming on previously cold snow. In other areas, the sun or greenhousing will have already cooked a slope, and you may not see as much avalanche activity. Some or all aspects could be crusty, and any north-facing crusts may not break down during the day. 

At mid and upper elevations, 1-2+feet of snow sits over the mid March crust. At upper elevations, that crust is hard and thick, whereas at mid elevations and southerly slopes it may be softer and thinner. Many spots in the Lower Elevation band may not have enough snow for you to see much avalanche activity. Near the top of the band, and other spots with a deeper snowpack, wet avalanche activity could still happen. 

This is a great weekend to get out in the backcountry. Wet loose avalanche activity is at least fairly predictable, so when temperatures start soaring and slopes start getting wet you can expect that avalanche activity may follow, and it's a good time to relocate. There's also many thin snow hazards, like obvious or sneakily hidden holes in the snow that might swallow you if you misstep. 

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