Bollettino valanghe

West Slopes North

Northwest Avalanche Center
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Pericolo valanghe

Fri
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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In sintesi

The avalanche danger is generally LOW, but you can find shallow wind drifted snow in near and above treeline areas. There are also isolated reports of natural avalanches on shady slopes above 5400 feet. Hard crusts beneath the new snow may make for challenging travel.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    1.5–2.5

    The potential to trigger an avalanche in the crust-facet layering from late January remains. The last reported human triggered avalanche on this layer was on February 5th, but four natural avalanches were observed in the last week on Shuksan, Table Mountain, Mt. Baker, and the White Chuck Glacier. Here is what we know: 

    • The layers are most prevalent on shady aspects above 5400 feet in elevation.  
    • There is around 2  feet of new snow above the weak layer.
    • Observed avalanche sizes are ~D2.
    • Snowpack tests produce inconsistent results, sometimes even in the same snowpit.
    • Many steep slopes where riders got out on with no results saw nearby slopes or another location on that slope avalanche on the weak layer. 

    Although the likelihood of triggering one of these avalanches is low, the consequences could be high if you are in a bad spot in the terrain. Remember, persistent slab avalanches can be triggered from low on the slope or remotely and factor in the consequences of triggering a large avalanche on the slope in question. 

    (2/12/2022)

    Natural avalanche suspected of failing in January 30th crust-facet layers. Estimated date of occurrence between Feb 8th-11th. East-northeast aspect at 6200' or Mt. Baker/Schriebers.

    Photo: Graham Clark 

Avalanche Discussion

Forecasts vary, but up to three inches of snow could fall during the day Thursday. If more snow arrives than forecasted, wind slabs could develop into larger deposits at mid to upper elevations. You might be able to trigger a small avalanche in thicker, drifted areas. Any avalanches would probably be inconsequential unless they added the miniscule amount of additional weight needed in isolated areas to trigger a persistent slab avalanche. 

New snow could be enough to soften surfaces a little more, as many upper areas currently exist as “dust on crust”. A very firm crust is on southerly aspects and all aspects below treeline. Observers reported a breakable crust on upper elevation, shaded slopes.

If you notice “weakening”, or faceting above the Valentine’s Day crust in the new low-density snow, let us know by submitting an OBSERVATION. A foot or more of snow could fall over the weekend, and knowing the characteristics of the layer it falls on is valuable information. 

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