Lawinenlagebericht

Lawinenlagebericht

Payette Avalanche Center
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Lawinengefahr

Mon
Hochgebirge
3 · Erheblich
Waldgrenze
3 · Erheblich
Unterhalb
2 · Mässig
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Kernpunkte

The Avalanche Hazard in the West Central Mountains is CONSIDERABLE today. Strong winds forecasted today and tonight along with new snow will make Natural Avalanches possible on wind loaded terrain, and triggering a persistent slab or recently formed wind slab is possible. 3 human triggered avalanches were reported on very weak and sensitive, well preserved large buried surface hoar (persistent weak layers) in the Lick Creek Area on Wednesday, Thursday, and even on Friday.

Be cautious in wind loaded as well as wind protected areas, avoid large exposed or sustained slopes steeper than 30 degrees, especially wind protected steep terrain where weak layers are best preserved. Cautious route finding, Careful snowpack evaluation, and safe travel protocols like exposing only one person at a time is essential.

Lawinenprobleme

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1–3

    Persistent weak layers are the theme! Almost every storm cycle, we have buried surface hoar and near surface facets as our major threat, and have been responsible for multiple skier triggered avalanches.

    The mountains received over 2 feet of new snow over the last week.  Now, there is a soft slab about 2-2.5 feet deep that formed over weaker snow and crusts below, which was the cause of the natural avalanche cycle early last week.

    3 skier triggered avalanches occurred one on Wednesday, one Thursday 2 peole took a ride and ended up ok, and even on Friday at the new/old snow interface up Lick Cr Canyon---Friday we remote triggered a large R4 D3 from the ridge when we felt and heard a large whoomph.

    Both of the other reported skier triggered avalanches, people described easy and rapid propagation over a large area on a slick crust. Triggering this slab is getting harder in most places as it is gaining strength, but as we found Friday, it is vey well preserved and very sensitive or weak in protected areas.

    Check your slope angles, and think about where might the weak layers have been able to survive the Sun and wind...Avoiding steep terrain and only putting one person at a time on a slope is still your best bet.  Adding the weight of new snow to these weak layers will be a test of the strength of them, and totally ruling out this problem is going to take more time than we would like, but continue to be paitient and catious as these weak layers are going to be here for a while. 

     

  • Wind Slabs

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

    Winds have been gusting from the southern portion of the compass this past week and have created sensitive wind slabs in leeward terrain. Today and tonight the winds will be out of the West into the 30plus MPH range. 

    Some older wind slabs are not cracking, but are resting on weak layers and are not bonded well at all.

    East and Northeast slopes will definately see some significant wind loading, but stay alert as terrain can influence wind loading differently from slope to slope and even across micro features on a slope.  Watch for stiff drifts and wind slabs on leeward terrain even well below the ridgetops. Avoid natural terrain traps like gullies.  Pay attention to the consistency and density of the snow under your skis, sled, or moto while you travel through different terrain.  A sudden change in the surface of the snow is a good indicator of wind slab formation.

      

     

    (2/6/2021) NE aspect of Sgt's (Brundage Mtn) Mitt pit about 7600ft on hollow wind slabs failing on isolation, 2-3 layers of buried surface hoar

Avalanche Discussion

There are multiple buried weak layers and crust/facet combinations in the upper portion of our snowpack right now. The addition of new and windblown snow on these layers is providing ample reasons to be cautious.   Preserved weak layers are hiding in protected areas...Today and tonight winds and soft snow will load leeward slopes...natural avalanches are going to become increasingly possible as well as human triggered avalanches through today and into tomorrow. 

If you see or trigger avalanche activity, please take the time to snap a picture and note the approximate elevation and aspect, you can submit an observation on our website. Getting your info helps forecasters and other users get a better picture of the conditions throughout our mountains. If you have trouble using our observations page, email us at: [email protected].

*Also, Please be mindful of other users, and where you are at. There are closures for motorized travel in and around the local ski areas, Granite Mtn, and other areas throughout our region.

***Check out the Winter Travel Map to find out where you can shred on your sled or moto.