Boletín de aludes

West Slopes North

Northwest Avalanche Center
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Peligro de aludes

Mon
Alta montaña
3 · Notable
Límite del bosque
3 · Notable
Bajo el límite
3 · Notable
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Desactualizado: este boletín caducó 4 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

Limit your exposure to steep terrain, in particular slopes with large glide cracks or cornices overhead. Though the peak of natural avalanche activity has probably come and gone, danger from large wet avalanches and cornice fall persists until the rain ends and temperatures cool.

Problemas de aludes

  • Wet Slabs

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

    Loose wet avalanches, wet slabs, glide avalanches, or cornices falling off ridgelines - all probably occurred in Saturday’s storm and rain event. The likelihood of seeing any of the above will lessen on Sunday with less rain.  The consequences of being in the way are the same.

    Wet slabs release with unpredictable timing and can occur in unusual locations - like in the middle or low on a slope instead of a higher, steeper start zone. You can identify potential glide avalanches by looking for large cracks, wrinkles, or snow blocks looming in steep terrain above. Sagging cornices will be easy to identify. It’s still a mystery if/when the slope will unload.

    The best you can do is to limit time spent on or under steep slopes or cornices. These aren’t the type of avalanches you can avoid triggering by sneaking around them. You are either in the way or not. 

    (12/23/2022)

    Natural wet slab avalanche below treeline at Mt Rainier. NW 3800ft. 

    Photo: NPS Rainier Rangers

Avalanche Discussion

Rainfall in West North ranged from 2-4” since Friday afternoon. Near treeline areas saw up to 1’ of wet, heavy snow and strong winds early on in the storm. By Saturday rain reached well into the alpine with Brown Top SNOTEL (elev. 5830’) hitting 35F. Winds raged with gusts to 59mph at Pan Dome.

There were no avalanche observations in the North Cascades - pretty much everybody took the hint and avoided the mountains. It’s still a sure bet that widespread, natural avalanche activity occurred Saturday based on the sheer quantity of liquid water dumped on the dry snowpack. There should be fewer avalanches on Christmas Day as rainfall backs off before another wet system forecast for Monday. The longer-term issue is that perched slabs and large snow blocks will remain a low-probability hazard for some time as seen in a tragic accident in the Baker Backcountry in 2016.  

Most ski areas and mountain pass roads were closed. An NWAC Forecaster attempted to make it to Lake 22 on the Mountain Loop Hwy in West Central. They turned around due to gushing creeks, rockfall, and generally miserable conditions. The main observation was the below treeline snowpack is taking a beating at the lowest elevations. 

 

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