Bollettino valanghe

East Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

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

We've just received a massive amount of new snow and very strong winds, so many slopes may be hanging in the balance, awaiting a trigger. Large and destructive avalanches could be initiated from wind loaded areas on upper elevations, as well as sheltered slopes at lower elevations. Stay off of, and out from underneath steep slopes -including roofs- while the snowpack adjusts to the load.

Problemi valanghivi

  • Wind Slabs

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

    Intense wind drifting of snow was observed Friday afternoon and may continue into early Saturday. This has created thick, and dense wind slabs in many areas. Dangerous conditions exist because these slabs may be hanging in the balance, waiting for a trigger. Very large, hard slab avalanches could be initiated from the edges of steep slopes or below. Cornices could collapse if you go near them and trigger very large avalanches. If triggered, these slides could be very deep and destructive.

    Keep your slope angles below 30 degrees. Stay well out from underneath any steep slopes with recent wind loading. Recognize that avalanches could be triggered even after a person or two, or three have been on the slope. 

    (1/7/2022)

    Intense wind drifting of snow was observed on Wedge Mountain Friday afternoon.

    Photo: Matt Primomo

  • Storm Slabs

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

    We've received a massive amount of new snow. The deep new snow is still stressing underlying layers, and may only need a trigger to create a large and surprising avalanche. In areas of the Wenatchee Mountains and the eastern foothills, avalanches have been breaking on the ground. Stay off of steep slopes, especially those in the eastern half of the zone where avalanches have been breaking to the ground. Be especially careful of very steep and convex features near ridgelines.

    Avalanches could occur in places that are not normally a concern like sledding hills and steep roadcuts near town. Roof avalanches will continue to pose a threat, so use caution and make sure children and pets stay well out from underneath areas of concern.

    (1/7/2022)

    Large slab avalanches in open hillside terrain of the Entiat drainage. North aspects around 1,500ft

    Photo: Ryan Graig

Avalanche Discussion

It was a storm for the ages for much of the East Central zone, and many areas including towns picked up a whopping 3-4ft of new snow in a two day period. A storm total of 50" with 2.9" of SWE was recorded in Leavenworth. The higher elevations surely have even more snow, but many of our weather stations are down and access to the higher mountains has been impossible. We have lots of uncertainty going into Saturday, but we do know that people have been reporting instabilities like many recent avalanches, whumphing collapses and shooting cracks from low elevation hills. I could make out large debris piles in many of the drainages in the lower Tumwater and Icicle Creek. Also on Friday, a very large hard slab avalanche ran on deeper crusts (4-6ft deep) at Crystal Mountain and on Thursday control work at Mission Ridge pulled out slabs on deeper layers.

There was a roof avalanche burial in Roslyn on Friday, with an elderly man. He was buried for 9 minutes, but luckily recovered alive with help of a quick response. Many roofs have been shedding and there have likely been many other close calls. On Thursday morning, an avalanche damaged a house south of Entiat. The residents were evacuated safely, but we are seeking more information on this slide. Tumwater Canyon remains closed, and WSDOT reported over 30 debris piles on the highway up to 15 feet deep. Roads have been hit by avalanches in many other areas including; Icicle Creek, Mission Creek, Olalla Canyon, and Entiat River rd.

Observers documented many different weak layers in the zone prior to the storm. The recent layers were large stellars, facets and surface hoar from 1/2 and 12/29. A decomposing crust from the Solstice was the bedsurface for some slides at Mission Ridge. An even deeper crust from Early December was observed to have propagation potential in the Icicle on high elevation slopes. At this point, these layers could be from 3-8ft deep, and act as the weak layer for slab avalanches.

Many great Observations have come in from the area. Thanks, and keep them coming as we unravel the saga of this epic storm.

Regioni coperte