Bollettino valanghe

East Slopes North

Northwest Avalanche Center
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Pericolo valanghe

Wed
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
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In sintesi

With strong to extreme West winds continuing to move new snow onto lee slopes through Tuesday morning,  you'll want to avoid traveling on or directly below wind loaded slopes capable of producing large avalanches.  Fresh cornices are growing larger - carefully consider the overhead hazard as you move through terrain. 

Problemi valanghivi

  • Wind Slabs

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

    While the storm cycle has delivered less new snow than forecast in the last 24 hours, the winds have not disappointed.  Touchy wind slabs reported on Sunday and Monday will only grow deeper on the same lee aspects overnight and at least through the first half of Tuesday as strong to even extreme westerly ridgeline winds continue. 

    Tuesday is not the day to dance around big terrain that has been wind-loaded.  Avoid large steep open lee slopes below ridgelines and cliff bands.  If you're traveling along ridgelines, give fresh cornices a large berth as they can easily break back further than you expect.  While unlikely, natural cornice fall can trigger an avalanche on the slopes below so be aware of your overhead hazard as you move about.  Larger avalanches are more likely near the Cascade crest where more new and recent snow is available for transport, however winds will likely be strong enough to build shallow wind slabs on open slopes below treeline.  Use caution in any elevation band you find firmer, wind affected snow.  

    In more sheltered terrain, you may trigger shallow storm slabs that fail on the old snow surface or inter-storm layers.  You can steer around steep rollovers and unsupported slopes to avoid triggering a storm slab avalanche.  

    (1/6/2023) Blowing snow coming off Blue Lake Col. 

    Freshly built cornices will tell you which slopes have been loaded over the last few days by westerly winds. 

Avalanche Discussion

Avalanche Accident Colchuck Pk, East Central Zone

We’ve received preliminary information of an avalanche incident on Colchuck Peak, SW of Leavenworth, WA. (East Central Zone) The accident occurred on Sunday, February 19 and involved a group of 6 backcountry travelers. Three members of the group are suspected to have been buried and perished in the event. Another sustained injuries and was evacuated by SAR.  Rescue efforts are ongoing. NWAC is working with Chelan County Sheriff’s office and will make updates as more information becomes available.

 Forecast Discussion:

On Monday, avalanche professionals in the Washington Pass area reported a large natural slab avalanche that released below the base of cliffs on a NE aspect below Blue Lake.  Blowing snow was observed near and above treeline and fresh cornices were growing along ridgelines.  This was a continuation of a trend that started Sunday, where shallow wind slabs (4-10") were developing and becoming increasingly sensitive as the day wore on.  Along some ridgelines, the winds were strong enough to scour down to the 2/12 crust (present up to about ~7000').  Prior to the current storm cycle, avalanche activity had been relatively limited dating back to the last avalanche cycle in this area between Feb 3-8th. 

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