Bollettino valanghe

West Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

Mon
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 2 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Identify and avoid steep terrain features where you find recently wind drifted snow.  Loose surface snow in more protected terrain will still run down the slope with human triggers or if provoked by snow shedding from cliffs warming in the sun. Avalanche danger is greater south of the Mt. Loop Highway in areas that received more new snow with the last storm.

West Central usually experiences a wide variety of conditions and also a lack of observations. It’s worth looking at the avalanche forecast for whatever zone is adjacent to where you are heading in the mountains.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Be on the lookout for fresh wind slab in addition to older slabs from the last storm. Northerly alpine winds should not be strong, but they will have access to plenty of soft snow to drift onto more southerly slopes. Expect to see more wind transport in the northern and eastern portions of the forecast zone.

    You are more likely to trigger a wind slab on steep, convex features just below ridgeline. Also, be wary of gully walls and unsupported areas above or around cliff bands. Blowing and drifting snow will show you which slopes are accumulating fresh wind slab. 

    Slabs from the last storm are probably trending towards unreactive, but it’s still worth evaluating the uppermost layers with hand pits, test slopes, and other informal tests. To find older slabs you will need to monitor changes in new snow depth and stiffness as you climb higher and change aspects. The depth of snow over the buried crust should serve as a convenient reference point. 

    (1/11/2025) 

    A human-triggered slab avalanche in wind exposed terrain. Snoqualmie Pass.

    Photo:  NWAC Public Obs

Avalanche Discussion

Partly sunny conditions should cause steep cliffy or treed terrain to shed snow and start loose snow avalanches on slopes below. Keep an eye on what is above you, especially during periods of warming or sun. Limit travel on or directly under sunny slopes where you see rollerballs or fresh loose snow avalanches.

Observations were mixed in the zones around West Central. West North reported plenty of wind drifted snow. Slabs up to 3’ deep over the crust buried on Jan 10th were easy to find but didn’t produce avalanches other than small labs 6-12" deep.  Loose dry avalanches were packing a punch and running full track to the bottom of the slope. 

Snoqualmie Pass produced numerous human-triggered slab avalanches on Saturday. Most were smaller and occurred in wind exposed terrain, but the number triggered speaks to lingering hazards in this area. Human-triggered slab avalanches were also reported from Stevens Pass.

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.

Regioni coperte