Lawinenlagebericht

West Slopes North

Northwest Avalanche Center
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Lawinengefahr

Wed
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
2 · Mässig
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Kernpunkte

Avalanche observations Monday demonstrate the continued risk of triggering a dangerous slab avalanche in alpine terrain. Consider the consequences of being caught in one of these avalanches before committing to wind loaded slopes. Cold temperatures and deep snow continue to elevate non-avalanche danger to backcountry travelers.

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    Avalanche mitigation work produced large avalanches in very steep, alpine terrain on Monday morning. They likely released within layers of storm and wind slab or at the Solstice Crust below the new snow. These avalanches create an additional degree of uncertainty in wind loaded avalanche terrain and should not be ignored. No other human triggered avalanches of this size and character have been reported in the West North. On the other hand, travel and observations in similar terrain are limited. Avoid very steep, wind loaded terrain to reduce the risk of triggering one of these avalanches, especially unsupported breakovers or hanging slopes above cliffs.

    Triggering a wind slab is still possible anywhere the wind becomes strong enough to drift plentiful light, new snow into a cohesive slab. Slopes with wind slab may be difficult to identify. Pay attention to areas where you are traveling closer to the snow surface on a dense supportable slab vs. moving through deep new snow. 

    (12/27/2021)

    Slab avalanche on Shuksan Arm in wind loaded terrain.

    Photo: MBSA

  • Loose Dry

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1

    Loose Dry avalanches, super soft storm slab avalanches - call them what you want, there is deep snow everywhere and it wants to go downhill. Observers report unconsolidated new snow with small, easy to initiate loose snow avalanches in steep terrain plus a handful of very soft slab avalanches. While few of these could be large enough to bury you outright, they could push you into a tree well or other hollow feature where you could become fully immersed and unable to extract yourself without assistance. The greatest danger is on slopes steeper than 40 degrees, especially those with trees, open creeks, or gullies in the track or runout. Move cautiously and be prepared for the snow to move with you in steep terrain - or simply avoid it to eliminate risk.

    An example of small loose dry avalanches in near treeline terrain

    Photo: Matt Primomo

Avalanche Discussion

Since December 21st near treeline areas across the West North received up to 5’ of new snow with some low elevation sites doubling their snowpack depth. Numerous, shallow wind slab avalanches triggered by backcountry travelers were reported on the 23rd through the 25th. 

On Tuesday high temperatures will make it out of the single digits and creep into the low teens. Prepare for unusually cold weather and stay alert to frostbite or other cold weather injuries. Deep, unconsolidated new snow will make for a significant snow immersion hazard around tree wells or other hollow terrain features. Have a plan to move through treed terrain and keep your partners in visual and/or verbal contact.

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