Avalanche forecast

Avalanche forecast

Payette Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 6 years ago.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

Highlights

The Avalanche danger is Moderate today above 7,000 feet. Human triggered avalanches are possible, especially in thin areas of the snowpack, and wind-protected terrain where persistent weak layers are more preserved in the upper snowpack and may be reactive to the weight of a skier or rider.   

Be cautious in steep terrain, utilizing safe travel protocols like exposing only one person at a time, and taking the time to dig in and evaluate the snowpack before committing to steep terrain.

Avalanche problems

  • Persistent Slabs

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

    Multiple weak layers exist within the upper 2-3 feet of the snowpack.  Most notably is buried surface hoar. These layers are reactive in our pit tests and relatively widespread on wind-protected slopes---mid-slope, or mid-mountain, where the wind and sun can't break down surface hoar, are likely places where it may linger, waiting for the right trigger. 

    The deeper of the two most obvious layers is is a buried surface hoar layer that produced a widespread avalanche cycle last week.  While the snow surface seems firm and unlikely to produce additional avalanches in many places, human triggered avalanches should be expected on slopes that did not experience natural avalanches during the storm cycle.   

    Wind loading over the last week has allowed weak layers to become buried much deeper in some areas and created hard, old, wind slabs resting on weak layers below. Variability from slope to slope is common right now as well. In some areas, the layer of near-surface facets and surface hoar has been preserved very well while on similar slopes nearby, environmental factors left less of these crystal types intact.  Safe travel and terrain selection is cheap insurance right now. 

    Buried Surface hoar Saturday on a North aspect failing in compression but lacking propagation on extended column tests...widespread surface hoar is currently forming on the snow surface

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1

    The wind has calmed down over the last couple of days, which has likely given time for a lot of slabs to bond.  Wind slabs are fairly widespread as a result and may vary from relatively soft to very firm and supportable to the weight of a skier. Older, hard wind slabs may be buried deeper in the snowpack and resting on buried weak layers consisting of buried surface hoar and near-surface facets. 

      Many of last week's avalanches occurred in deposition zones that were well below ridgelines where the weak layers are still preserved.  High winds will load slopes in unusual ways.  Your best bet is to watch for visual clues of wind effect and pay attention to the density of the snow surface as you travel.  

     

    Wind Effect on the snow surface...looking at a SE Slope on Squaw Point on Frday

Avalanche Discussion

The snowpack is a mixed bag right now.  There are multiple overlapping problems within the snowpack that are blurring the size and boundaries between problem layers. Big lines are starting to fill in and ski conditions are improving. Now is definitely not the time to get lured into big, exposed terrain.  Local guides and forecasters are giving the snowpack a low confidence rating and avoiding steeper terrain. 

Choose your terrain wisely and take the time to dig in and see what's going on in the snowpack before you cross the line into more committing terrain.

Deep In our snowpack, Low Probability High Consequence: Almost all aspects have the common factor of very weak and fairly to heal, loose, faceted snow in the lower snowpack that was buried around December 14th.  These deep layers are getting hard to trigger in most areas but seem to be more easily triggered in the mountains to the south of McCall.   Avalanches triggered in these deep layers would likely be unsurvivable based on the size and density of the slab above them, continue to practice safe travel protocols in and around terrain steeper than 30 degrees.

Our observations page is growing, but we are still working out some bugs.  If you are submitting an observation and are having trouble, please send us a description of the problem.  You can email your observations to us as well.  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. Photos of recent avalanches are also very helpful to the forecasters with a short description of aspect, elevation, and relative location.

*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.