Bollettino valanghe

West Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

Mon
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
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In sintesi

Large natural avalanches remain a threat until the rain ends and temperatures cool. Be wary of traveling on or under steep slopes, in particular those with large glide cracks or cornices overhead. Raging creeks and other hazards could make for difficult travel on low-elevation trails and snowshoe routes.

Problemi valanghivi

  • Wet Slabs

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

    Most areas of West Central received 2-4” of good old liquid water instead of the freezing rain that fell on Stevens and Snoqualmie Pass. While plenty nasty, it’s possible the rain crust capping the snowpack may have delayed the onset of natural avalanche activity. Check out the forecasts for the Passes if you are traveling near those zones.

    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

Most areas of West Central received 2-4” of good old liquid water instead of the freezing rain that fell on Stevens and Snoqualmie Pass. While plenty nasty, it’s possible the rain crust capping the snowpack may have delayed the onset of natural avalanche activity. Check out the forecasts for the Passes if you are traveling in neighboring areas of West Central.

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. They turned around due to raging 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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