Bollettino valanghe

East Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

Mon
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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In sintesi

Keep an eye out for wind-affected snow in exposed, downwind terrain in areas that received more new snow recently. If you see signs of instability such as cracking, collapsing, and recent slab avalanches, steer around slopes steeper than 35 degrees.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    Wind slabs are more unstable closer to the Cascade Crest. Read the forecasts for Snoqualmie Pass or Steven's Pass if you plan to recreate near the Crest close to those zones. Wind-loaded terrain can often be found just below ridgelines and in cross-loaded gullies. You probably won't see blowing snow so look for other clues such as cornices, soft pillow-like slabs, or denser, uneven snow surfaces which all indicate previous snow transport. Hop on a small, low-angle test slope representative of the slope you plan to ski or sled to check for cracking and collapsing. If you see signs of instability or recent slab avalanches, stick to lower angle, wind-sheltered slopes.

    (1/11/2025)

    I was able to trigger stubborn cracks in wind loaded snow in the East Central zone on 01/11. These slabs wanted to slide on a slick crust about 6 inches below.

    Photo: Payton Schiff

Avalanche Discussion

Saturday morning, a group of four backcountry tourers were involved in an avalanche accident near Kendall Peak in the Commonwealth Basin area of Snoqualmie Pass. Details are still being gathered, but the accident occurred on a SW aspect at 5600ft. All four members were caught and carried. Two were injured. The party called 911 to request assistance. Search and rescue responded to the area and brought the victims to the trailhead.

An NWAC Forecaster traveled to the Salmon La Sac on Saturday to investigate the presence of wind slabs. She found stubborn slabs in exposed terrain starting at 5000 ft. These slabs were on average 6 inches deep and wanted to slide on a slick melt freeze crust below. You can check out the full observation here.

Especially on slopes that see direct sunshine, you may encounter surface snow that is warming and weakening. Snow shedding off cliffs/trees and rollerballs/pinwheels indicate that the snowpack is losing cohesion and beginning to move. If you begin punching deeply through the snowpack and the snow feels heavy and sticky, consider moving to shadier slopes.

If you've ever found yourself wondering which direction you should look for wind loading if you encounter rippled, uneven snow surfaces, the best way I have found to think about it is that the "pointed" ridges of the ripples "point" towards the prevailing wind direction. It is a similar concept to how riming on trees usually happens on the side of the tree facing the wind.

Help NWAC Forecasters reduce uncertainty by submitting an observation!

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