Lawinenlagebericht

Silver Valley & Bitterroot Mountains

Idaho Panhandle Avalanche Center
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Lawinengefahr

Sat
Hochgebirge
3 · Erheblich
Waldgrenze
3 · Erheblich
Unterhalb
3 · Erheblich
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Veraltet — dieser Lagebericht ist 5 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

Lots of new snow and winds have created wind slabs and crossloading on multiple aspects. Stay vigilant of your surface conditions: there will be lots of red flags to watch for out there today. Our buried persistent week layer is now in the deep category.  It will be harder to trigger, but the consequences will be much bigger if it does go. Storm slabs or wind slabs that are triggered higher in the pack have the ability to step down to create a much bigger avalanche.  The snow is nice and light and fluffy, so have fun playing it safe on conservative terrain. 

Lawinenprobleme

  • Wind Slabs

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

    Wind gusts yesterday and last night reached into the 40 mph hour range.  While they were predominanatly from the SW, loading our start zones on the NW-N-NE aspects, they shifted and swirled enough to create problems everywhere.  Watch for cross loading in gullies and micro features that trap the snow on the south facing sides even.  Pay attention to the surface of the snow, watch for chalky, pillow like snow that is dense and hollow sounding as you travel over it.  This problem will get worse as you get higher.

  • Storm Slabs

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

    We picked up anywhere from six inches to a foot of new snow in the last 24 hours of nice low-density powder.  It wasn't slabbing much yesterday, but it might settle and consolidate enough today that we start seeing slabbing.  Up high this might be on top of wind slabs from earlier this week, giving it a nice hard surface to slide on below.  At the lower elevations, on the elevations, we were getting small slabs to slide during ski cuts on the Monday rain crust.    

  • Deep Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    2–3

    Well, our buried persistent weak layer didn't go away with the new storm, it just got buried deeper!  Many locations are still showing results of this in pit tests.  When you are digging pits to test your slope, make sure to go all the way down to the January rain crust.  The buried layer is resting a couple inches above that.  We also have graupel layers in there that are being reactive; this problem isn't as widespread, but something to note.  An avalanche in the upper layers has the potential to step down and trigger a slide in this layer.  Or that big trench that digs down 3 ft before you get momentum.  

Avalanche Discussion

The snow yesterday and last night was nice and light density, which made for great riding and sliding conditions. Yesterday, we found it most enjoyable from 4000' to 5000', above that it was too wind affected everywhere. Chasing the good snow makes it easy to avoid those upper elevation wind slab problems! Win-Win.  While we were not able to find the deep buried persistent weak layer where we traveled, there are observations from other locations in the region that still had it full propagating in pit tests.  We also had a snowmobile trigger on it earlier in the week.  It still isn't trustworthy enough for me to step into bigger terrain.  It's a patience and human factor game right now. Don't let yourself loose your avalanche caution. 

Observation contest is still going on through the weekend for the month of February, more details here. 

March 2nd, there will be a live Q&A Raffle and chat, more details here. 

 

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