THIS AVALANCHE ADVISORY EXPIRED ON January 5, 2016 @ 6:39 am
Avalanche Advisory published on January 4, 2016 @ 6:39 am
Issued by -
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The Avalanche Hazard remains MODERATE at upper elevations, above 7,000 feet where the possibility of triggering a wind slab in steep wind loaded terrain still exists. These wind slabs are scattered near ridge tops and in other terrain features that caught last week's blowing snow.  Exercise caution in all steep, consequential terrain...

In non-wind loaded terrain, below 7,000 feet, Avalanches are possible but not likely: stability is good and the Avalanche Hazard is LOW.

How to read the advisory


  • Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Wind Slab
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The possibility of triggering wind slabs is still lingering in the upper elevation areas near ridge tops and in a few pockets where blowing snow can accumulate. You will find them mostly on the north half of the compass and scattered on east and west aspects.  Be weary of cross loaded slopes in the upper elevations where shifting winds have caused inconsistent loading. 

Most of these wind affected areas are going to be pretty obvious as a density change or an area of stiffer snow in the otherwise soft snow around them. Look for them below cornices, on steep roll overs, and in gullies or small depressions on the slope.You can also see what the wind has been doing, look for drifts, spines or areas of sculpted/scoured snow.  These visual clues are pretty obvious if you can see the terrain around you.  The wind slabs that we have been finding this week are shallow in most areas and only reactive on steeper terrain. Keep in mind that wind slabs are commonly triggered from thin areas, or edges of the slab.

Avalanche Problem 2: Loose Dry
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The intermittent sun from the last few days is helping consolidate the snowpack, which is reducing the chances of wide spread loose dry avalanches. With the increase in temperatures yesterday and today expect to see this loose powder snow consolidate even further with the exception of high elevation, shady aspects. These small slides don't pack a lot of punch but can grab you and push you in a direction you don't want to go whether you are on a sled or skis. These slides are an indicator of how good the snow is staying in protected areas, it takes light dry snow to create a sluff.

advisory discussion

Well we had a great month of December with great snow and good stability...Now that 2016 is here we might start to see some more erratic snow and avalanche conditions to our area. A combination of crusts, surface hoar (only in sheltered areas where the winds have not broken it down), and small pockets of wind slabs will make any future dumps of snow more suspect to avalanche. So as we move forward into the great year of 2016 as the snow begins to pile up, remember to ride/ski smart and not get complacent about the snowpack below you.

recent observations

While out touring yesterday up Lick Creek we saw more evidence that our snowpack is gaining strength. We are seeing some good settlement(sintering)...a great base for the beginning of January. The sun has put a fairly substantial crust (2-4 cm) on the surface, especially due south-southwest. This crust is/will start to cause us problems when we get a new snow load on top of it and it becomes a great surface for loose slabs to run on. The crust along with pockets of surface hoar (small grains only found in shady protected areas) will definitely need to be watched as we move forward through the winter.

Travel smart in the backcountry by exposing only one person at a time when on or near avalanche terrain, especially above 7,000 feet where the wind has loaded slopes, and developed slabs. Wear and know how to use your beacon, probe, and shovel. 

  • Skiers and riders are getting into some of our more consequential terrain...make sure that you have an escape route planned if something goes wrong: if you do trigger a wind slab in a steep, wind loaded start zone, you may take a long ride into rocks, or possibly off a cliff.

 

weather

Cloudy skies will be over the advisory area today with south winds reaching into the 20 mile per hour range. Temperatures will be near 32 degrees at upper elevations. A chance of snow comes back to the West Central Mountains tomorrow morning with .2 to .4 inches of water (approx. 2-4 inches snow) falling by Wednesday mid day. 

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Monday Monday Night Tuesday
Weather: Cloudy, with a high near 29. Calm wind. A 30 percent chance of snow, mainly after 11pm. Cloudy, with a temperature rising to around 28 by 11pm. Light east southeast wind. New snow accumulation of less than a half inch possible. A 30 percent chance of snow, mainly before 11am. Cloudy, with a high near 33. Light south southeast wind. New snow accumulation of less than a half inch possible.
Temperatures: High 29 deg. F. 28 deg. F. High 33 deg. F.
Wind direction: south east-southeast south-southeast
Wind speed: calm light light
Expected snowfall: 0 in. less than half inch in. less than half inch in.
Granite Mountain at 7700 feet.
  Monday Monday Night Tuesday
Weather: Cloudy, with a high near 32. Breezy, with a south wind around 22 mph. A 40 percent chance of snow, mainly after 11pm. Cloudy, with a temperature rising to around 30 by midnight. Breezy, with a south wind 21 to 23 mph. New snow accumulation of less than one inch possible. A 40 percent chance of snow. Cloudy, with a high near 31. South southwest wind around 18 mph. New snow accumulation of less than one inch possible.
Temperatures: High 32 deg. F. 30 deg. F. High 31 deg. F.
Wind direction: south south south-southwest
Wind speed: 22 21-23 18
Expected snowfall: 0 in. less than one inch in. less than one inch in.
Disclaimer

This avalanche advisory is provided through a partnership between the Payette National Forest and the Payette Avalanche Center. This advisory covers the West Central Mountains between Hard Butte on the north and Council Mountain on the south. This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires at midnight on the posted day unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.