Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

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

If you’re planning on taking advantage of the nice weather in the mountains on Friday, don’t let your enthusiasm affect your decision-making. There may still be overlapping avalanche problems in the new snow for you to manage. 

Avalanche problems

  • Wind Slabs

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

    At upper elevations, you could still encounter lingering slabs where the wind has piled the snow into deeper drifts. Look for these near ridgelines or in confined chutes and gullies. Recently formed cornices or smooth pillow-like piles that look “fat” can help you identify the wind-loaded features that you should avoid.

    In less wind-effected areas, you might encounter Dry Loose avalanches in the most recent storm snow. These slides could potentially run far and fast if they entrain down to the MLK crust and will be more likely on steeper features. Don’t get swept off your feet by one near terrain traps or on a consequential slope.

    (1/16/2023)

    A skier triggered Wind Slab from earlier this week that likely ran on the MLK crust. This slab was found on the lee side near ridgeline. [NW 6400']

    Photo: Public Observation

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Speaking of loose avalanches, it should be a beautiful day around the zone, with a bump in freezing levels and more sunshine. On Thursday, the sun came out and helped produce some rollerballs and shedding snow from cliff bands in some areas of the zone. That doesn’t mean it happened everywhere, so we could be in store for more on Friday. If you notice that the snow surface is getting wet due to the sun’s influence, snow is shedding from trees and rocks, or see new rollerballs/pinwheels, then you should start thinking about Wet Loose avalanches. Like their dry counterpart, these slides like to start at a point and fan out as they descend. Your best mitigation tactic will be to head for shadier or lower-angled slopes. In some areas of the zone, these slides may be so small at lower elevations that they're not of consequence.

    (1/19/2023)

    In the neighboring Snoqualmie Pass zone, a Wet Loose avalanche occurred as a result of a tree bomb during a period of sunshine on 1/19. [S 5200']

    Photo: Zack Novak

Avalanche Discussion

Friday should be a beautiful day around the West South zone with plenty of sunshine and fairly calm winds. The recent storm dropped anywhere from 5-9 inches of snow around the zone, with the volcanoes being on the higher end of those storm totals. 

This puts about 1.5 feet over the MLK crust at mid to upper elevations, with significantly less lower down. These depths could vary some around the zone, particularly from crest to volcano, but it shouldn’t be hard for you to find this prominent snowpack marker. The snow above it is the target area for any avalanche you might encounter on Friday. In some cases, slides could end up running on the crust. There has been a reportedly poor bond to the MLK crust in many areas of the zone and multiple avalanches were triggered on the snow above it last weekend. That bond may have improved some in recent days, but may not be fully trustworthy. Take the time to investigate all of the snow above the MLK before committing to a slope.

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