Avalanche forecast

Avalanche forecast

Payette Avalanche Center
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Avalanche danger

Wed
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
Out of date — this forecast expired 6 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

The avalanche hazard is Considerable today.  Human triggered wind slab avalanches up to 2 feet deep are possible as an aproaching storm brings heavy new snow and strong gusty 20 MPH winds loading lee terrain. You are most likely to trigger  Deeper avalanches where the snowpack is thin, on North aspects, and in protected areas where older weak layers are still present and have been preserved.  Our snowpack is weak near the ground and hard to trigger putting us in  a low probability high consequence scenerio. 

  

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    The approaching storm today is forecasted to put down up to 2 feet of snow over the next 24 hours and will come with some strong gusty South, Southwest winds cranking into the upper 20's at times.  Some loaded slopes may develop slabs up to 4 feet deep. Be cautious near ridgelines and on wind-exposed slopes.  Pay attention to obvious clues as to which way the wind has been blowing; ripples across the snow surface, wind lips, or drifts are great visual clues. 

    Local variations in terrain can influence wind loading on slopes that may not be on your radar.  Red flags like shooting cracks, or hollow feeling or sounding snow should turn you around in your tracks.  Wind slabs may have the ability to step down into deeper layers below creating much larger avalanches with much higher consequences.

    Wind slabs growing on Monday Jan 11, 2021 North of McCall above Serene Lake

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Storm slabs are going to grow today as temperatures warm and the snow piles up. Over the last week we have seen some big surface hoar growing and will now be getting buried under denser snow. The recent Wind and Sun have likely broken down the surface hoar in some areas, but areas protected from the wind and Sun (like steep rollovers mid-slope) are going to be more likely to have a sensitive slab that struggles to bond. By the time you notice red flags like cracking, it may be too late.  Steep protected terrain wil be suspect for the near future.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3

    Our snowpack has a few weak layers right now.  Triggering these weak layers is getting much more difficult, but if you do you may trigger a large unsurvivable avalanche. Its the classic low probability/high consequence scenerio. The weak layers failed naturally on a lot of steep slopes around December 21st, but not all...not good enough to count on them being gone, so the take home point is you can get away with a lot right now but the land mines might still be out there. The overall strong over weak structure does not inspire great confidence right now in the snowpack.

    In the upper 2 feet we are getting moderate results in compression, but no propigation on extended column tests where crusts, small-grained facets, and degrading surface hoar are present depending on your aspect.  Deeper in the snowpack is a lingering, slow to heal layer of loose, larger grained faceted snow that refuses to go away. With the overlying slab becoming more consolidated, denser, and continuing to get thicker, the consequences of triggering an avalanche in this layer are going up with every storm. 

    While we are not seeing natural or human triggered avalanches since last week, the potential for deep slab skier and snowmobile triggered avalanches remains.  Choose your terrain wisely and keep an eye on your partners.  Don't ski out of bounds near the ski areas without the proper safety and rescue equipment. 

                           

     

    Test Pit on Monday

Avalanche Discussion

Our observations page is growing...Thank you to everyone that has been sending in observations this year!  These help the forecast team form a clearer picture across the forecast area. We will be continuing to improve the observation form to make your submissions even easier over the next few weeks.

Also, resort and backcountry skiers leaving local ski areas need to be aware that areas outside of the ski area boundary are not patrolled, have no avalanche control work being done in them and if you are injured skiing or caught in an avalanche, the ski patrol has no obligation and may not have the resources to assist you.  Backcountry rescues are subject to the direction of the Sheriff's department and Search and Rescue Teams.  Rescue could be hours away, even close to the ski area.  Self-rescue is your best option and that means that everyone in your party should have the gear, understand the risk, and have the ability to provide an avalanche rescue and to perform basic life-saving medical skills.  The backcountry adjacent to resorts has some of the statistically highest concentrations of avalanche incidents and fatalities every winter no matter where you are.  Thanks to the Friends of the Payette Avalanche Center and our local resorts, you will now see beacon checkers at our backcountry gates.  This is a great reminder of the risks you face when you leave the ski area.

Our friends at the Sawtooth Avalanche Center will be hosting a FREE online Introduction to Avalanches Class on January 14, this is a great opportunity to get some basic knowledge or brush up on your avalanche basics if you have not taken a class in the last few years.