THIS AVALANCHE ADVISORY EXPIRED ON January 3, 2016 @ 5:35 am
Avalanche Advisory published on January 2, 2016 @ 5:35 am
Issued by George Halcom - Payette Avalanche Center
bottom line

The Avalanche Hazard is 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
  • Character ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

 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.  

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 natural catcher's mitts like 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
  • Character ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

The Sun is helping consolidate the snowpack. Northern, shady aspects will have deeper snow. Small loose, dry avalanches or sluffs should be anticipated on large steep, steep confined slopes or on slopes with obstacles below your intended line. 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.

Avalanche Problem 3: Loose Wet
  • Character ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

The Sun is putting out some heat on the Southern aspects. Solar radiation, and warmer temperatures today have the potential to kick loose point releases, especially in steep terrain that faces due South. Theese small avalanches will be most likely in rocky, shallow terrain. While small, they could cause you to ski or ride into an area you may not want to. You will also notice a thin crust forming on the surface of Southern aspects surface from the sun.

recent observations

Our snowpack is fairly strong. We are seeing some good settlement...a great base for the beginning of January. The sun is putting thin crusts onthe surface, especially due South. A strong snowpack is great news, however, you should not let your guard down. 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? 

 

CURRENT CONDITIONS Today's Weather Observations From the Granite Weather Station at 7700 ft.:
0600 temperature: no data deg. F.
Max. temperature in the last 24 hours: deg. F.
Average wind direction during the last 24 hours:
Average wind speed during the last 24 hours: mph
Maximum wind gust in the last 24 hours: mph
New snowfall in the last 24 hours: inches
Total snow depth: inches
weather

Today we will see bright sunny skies,and warmer temperatures, closer to freezing in the upper elevations.Tonight,clouds will develop with a slight chance of snow, and a possibility of a wetter pattern developing, but there is a possibility of a split in the storm track?

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Saturday Saturday Night Sunday
Weather: Patchy fog before 11am. Otherwise, sunny, with a high near 15. Wind chill values between -6 and 4. Calm wind. Increasing clouds, with a temperature rising to around 16 by 5am. Light and variable wind. A 20 percent chance of snow. Mostly cloudy, with a high near 24. Calm wind.
Temperatures: 15 deg. F. 16 deg. F. 24 deg. F.
Wind direction: Calm Light and Variable Calm
Wind speed: 0 0 0
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Saturday Saturday Night Sunday
Weather: Sunny, with a high near 22. Wind chill values between -6 and 4. South wind 9 to 13 mph Increasing clouds, with a temperature rising to around 22 by 5am. Breezy, with a south wind 15 to 20 mph. A 20 percent chance of snow. Mostly cloudy, with a high near 28. Breezy, with a south wind 16 to 20 mph.
Temperatures: 22 deg. F. 22 deg. F. 28 deg. F.
Wind direction: S S S
Wind speed: 9-13 15-20 16-20
Expected snowfall: 0 in. 0 in. 0 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.