Bollettino valanghe

Silver Valley & Bitterroot Mountains

Idaho Panhandle Avalanche Center
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Pericolo valanghe

Sat
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
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In sintesi

Cold temperatures, persistent weak layer, and wind slabs will the story of the weekend.  The new snow from last weekend has started to stabilize and bond together, but it is still sitting on top of a very weak layer of buried surface hoar.  This is buried 20 to 30 inches (50 to 75cm) down widespread across the forecast area, in the sheltered areas as well as on open slopes.  It isn't as easy to trigger as last weekend, but it is a problem that is going to stick with us for a while. And when I say a while, it could be weeks.  Stay vigilant!

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    2–3

    This layer isn't going anywhere on us for a while, so we will need to be patient and conservative.  It's easy enough to find in the snowpack: dg down until you hit the ice, then look a couple inches above the ice.  Persistent weak layers will often show up as a gray line in the snowpack due to the air in between the crystals.  Yesterday we were finding pockets where it was still intact that were up to 2cm big!  This will be a tricky layer to assess for as well: you might dig a pit and check for this layer, but not get any results in you pit tests because at your location it has already collapsed.  A hundred feet over, the layer might be alive and well and that is where you can trigger an avalanche.  As you are traveling, listen for whumphing and collapsing, and watch for shooting cracks. These are red flags that are telling you to stay out of avalanche terrain.  

    (2/11/2021) 2cm buried surface hoar with Mikey's icey beard for scale.

  • Wind Slabs

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

    Winds have been predominantly out of the North, which is ushering in all the cold temperatures.  A couple inches of light density snow from Wednesday were being blown around easily yesterday forming soft but sensitive wind slabs. Watch for chalky, hollow, pillow looking snow. Expect them on aspects that you aren't usually used to.  

Avalanche Discussion

BRRRRR!  If you aren't used to the cold temperatures that we are experiencing right now, that is the biggest danger you will face this weekend.  Wear lots of layers, try to avoid sweating, and have healthy group discussions of how you might change your travel or risk exposure due to the cold temperatures. Any accident has the potential to become way worse when the thermometer is hovering around zero.  

Patience, that seems like a running theme for this winter season.  Right now I ask you to have patience to wait out this persistent weak layer problem.  It's not going to go away overnight, or even in a weeks time.  The consequences of triggering it are a very big slide.  This past week has been especially hard on the backcountry community across the West, none of us want to be the next statistic.  But lucky for us, the powder from last weekend has consolidated some and the low angle skiing and riding is spectacular right now.

Other things of interest: 

We are extending the application period for the Abromeit Scholarship.  This is a chance at a Level 1 class for folks between the age of 14 and 24.  See more details on how to apply here. 

We are also still running our observation contest.  Congrats to all the winners for the month of January!  But don't fear if you weren't drawn, you still have a chance for the month of February.  Check out the details here.  Thanks to everyone so far that has submitted observations, they are so helpful in keeping us all safer.  

 

 

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