Bollettino valanghe

Stevens Pass

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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Non aggiornato — questo bollettino è scaduto 6 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Update 8:30pm: A natural avalanche cycle may occur Saturday night, and dangerous conditions will linger into Sunday. Recent human triggered avalanches have occurred on a number of weak layers, which will only be deeper on Sunday. You could trigger a storm slab up to 4ft deep. Steer around steep open slopes as well as sparsely treed terrain at all elevations while the snowpack adjusts to this big storm load.

Problemi valanghivi

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    2–3

    Steer around open slopes 35 degrees and steeper until the snowpack has a chance to adjust to this hefty new load. On Saturday, two reports came in of human triggered avalanches on a recent suncrust at around 5,000ft. One of these was 200ft wide and 1.5-2ft deep. Any avalanche triggered in the recent snow could step down deeper to the crust from 12/21. This crust may be found 3 to 4ft deep, with weaker, dry snow just above it. With all of the uncertainty, it'll be best to stay off of slopes steep enough to avalanche. As you travel, take a look at which layers are failing and consider the consequences of even small pieces of steep terrain.  As you ascend in elevation or travel into wind affected terrain, remember avalanches could be deeper and more destructive the higher you go.

    (1/1/2021) Testing storm snow layers on a small unsupported slope.

Avalanche Discussion

We’re more than 5 days into a prolonged storm cycle at Stevens Pass. Snow continues to pile up, especially at mid and upper elevations. As the storm totals grow so does our uncertainty. Any avalanche has the potential to entrain additional snow, grow larger and become destructive.

On Saturday morning, WSDOT avalanche team triggered some large slides down to the 12/21 crust. A few reports also came in on Saturday of slides being triggered on a suncrust from 12/29. These were on South aspects at 5,000ft. One was 200ft wide. On Saturday night, ski patrol found very reactive conditions, and triggered D2 avalanches on the new/old interface. In short, there are plenty of recently buried weak layers, and they all demand respect. On Friday I found weak structure with the 12/21 crust throughout a range of aspects and elevations, and snowpack test results suggested that the crust can fail and produce avalanches. While triggering this layer might be difficult due to the strength of the overlying snow, if it failed the resulting avalanche may be very large. You may find the prominent 12/21 crust and it’s associated facets 2-3’ below the snow surface. Avoid traveling in obvious starting zones and steep open slopes where this layer cloud roar to life. 

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources. Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

Regioni coperte