Boletín de aludes

West Slopes Central

Northwest Avalanche Center
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Peligro de aludes

Mon
Alta montaña
2 · Moderado
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil
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Desactualizado: este boletín caducó 7 months ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

Avalanche danger will depend on how much new snow you find. Areas with only a few inches of new snow should have minimal avalanche danger. Where around 6 inches or more accumulated, watch for wind-drifted slabs and the potential for wet avalanches on sunny slopes.

Problemas de aludes

  • Wind Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1–2

    Assess the bond of recently formed wind slabs before committing to steep terrain. The latest round of slabs is likely dense and stubborn to trigger, but could be more reactive where they formed over a slick crust. Brief sun breaks and warming could also increase reactivity. This is primarily an upper-elevation problem, where the most new snow accumulated, though small slabs might also be found at mid elevations. 

    Strong winds and snowfall are forecast to back off by morning, so active loading should be over by the time most people are in the mountains. Cornices and scoured slopes can help you identify wind-loaded terrain. Use hand pits, test slopes, and other informal tests to assess slab bonding before stepping onto steeper slopes.

    (1/14/2024)

    Rime, scoured slopes, and drifts can help you figure out local wind patterns and anticipate potential wind slabs. 

    Photo: Dallas Glass

Avalanche Discussion

Wet loose avalanches are possible on sun-exposed slopes where there is enough new snow to react to warming, mainly at upper elevations. If middle elevations pick up more than an inch or two of new snow, the same pattern could show up there. Without both sun and new snow, wet loose activity remains unlikely. Keep an eye on what is happening above you as the day warms up.

Sunday will be one of those days where you just have to go see what you find. There should be significant variation in precipitation and snowfall amounts across the forecast zone, and cloud cover remains highly uncertain. Fortunately, it should be relatively easy to determine actual avalanche danger wherever you are by paying attention to new snow amounts and sky cover.

By the end of Saturday, the north-to-south shift in precipitation was apparent. The Heather Meadows weather station in West North picked up nearly 1.50 inches of precipitation in the form of rain and then wet snow by 4 p.m. Weather stations around West Central averaged around an inch of precipitation over 24 hours, while Stevens and Snoqualmie Passes received 0.25 and 0.50 inches, respectively. While much of this fell as rain, 1–2 inches of wet snow had accumulated at 5000 feet. The only reported avalanche was at Stevens Pass, where rockfall got a small amount of wet snow moving on the slope below.

An NWAC forecaster in West North reported moist new snow rapidly accumulating in the late afternoon as snow levels and temperatures lowered. Winds were howling, but the new snow was sticky enough at mid elevations to resist wind transport. No new avalanches were reported, though visibility was too poor to see much of the surrounding terrain.

Regiones cubiertas