Boletín de aludes

East 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 5 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

Continued very warm temperatures are likely to cause more wet avalanches. Wet loose avalanches can be triggered easily, and both glide and cornice avalanches can release without warning. Avoid going on steep slopes if they are unsupportable, and plan your exit to steer clear of overhead hazards.

Problemas de aludes

  • Loose Wet

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

    Snow surfaces will quickly become wet and unsupportable, and I wouldn't expect much, if any refreeze. Wet avalanches may first become active on northeast aspects and later on south, and then west aspects. Take note of what the snow surfaces are like. Do you punch through easily, or stay on top? If the snow is unsupportable and punchy, it is probably weak enough to entrain an avalanche. These slides have begun to occur even on north-facing slopes, and slides on most aspects could gouge down into deeper layers. It will be safest to avoid steep slopes, and especially big complex terrain as this sustained very warm period.

    If you choose to go into the mountains, plan your exit strategy to avoid steep slopes and stay well out from under places with overhead dangers.

    (4/16/2021) Example of recent wet loose avalanches from the Stevens Pass zone.

  • Glide Cracks

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    2–3

    Look out for glide cracks, or crevasse-like cracks on steep slopes. These may release spontaneously, creating very large and destructive avalanches. Similarly, cornices loom over some ridgelines, have been dripping, and may fail with the hot temperatures. Use extra caution to avoid being on or under slopes with glide cracks and cornices.

    Water has also begun to run through the lower elevation snowpack and many glide avalanches have been releasing. With both of these red flags in mind, along with continued soaring temperatures, more glide avalanches are expected to release. 

    (4/17/2021) Several glide avalanches in the Goat Mountain area. The leftmost one, on Goat Mountain - West was seen on Friday, but the other two weren't reported until Saturday. Photo: Jason Speer

Avalanche Discussion

A sustained very warm period will continue through Sunday. Upper elevations haven't seen below freezing temperatures since the 14th. With these very warm temperatures, meltwater is beginning to filter deeper into the snowpack. This is quickly changing our snowpack from a dry winter-like pack to a wet and mushy one. Glide activity has been picking up, and many more recent glide avalanches were observed on Saturday in the adjacent West North zone. Many of these were D2-D3 in size, but smaller ones from the Cutthroat Paths above Hwy 20 were reported on Friday. If you go for a bike ride up Hwy 20 over the weekend, consider that these avalanches could run without warning, and hit you on the pavement.

WSDOT highway forecasters have been working to clear Highway 20. On Thursday, they dug a profile on a southeast aspect at 4,000ft in one of the Cutthroat avalanche paths. They found over 5 feet of snow on the ground with a couple of recent storm layers in the top foot of the snowpack and a layer of rounding facets near the ground. Since the 7th, two storms brought a total of 6" to 1 foot of snow. 

This is the final full avalanche forecast product of the 2020-21 season. As our capacity thins during the warmer months, please continue to share your observations and make use of our mountain weather forecasts (daily through the end of April). From all the forecasters at NWAC, thank you for all your support that makes this product possible and we look forward to resuming full operations in late 2021.

Daily avalanche forecasts will end on Sunday, April 18th. 

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.

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