THIS AVALANCHE ADVISORY EXPIRED ON January 6, 2016 @ 7:02 am
Avalanche Advisory published on January 5, 2016 @ 7:02 am
Issued by George Halcom - Payette Avalanche Center
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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, and recent snow this week.  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 ?
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  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
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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. Fresh, shallow slabs were forming yesterday, withlocalized cracking around skis. You will find them mostly on the north half of the compass and scattered on east and west aspects where cross loading has occured. 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.

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

We toured out East of Boulder Mountain yesterday. We covered a lot of ground. The only activity we saw was a very steep, 50 degree, wind loaded rocky face below Buckhorn MT peeledd off leaving a very small piece of debris. The snowpack has settled a lot due to time, and gradual warming. Loose avalanches are not likely a threat any longer. We barely had any sloughing going while skiing 40 degree slopes. North West winds the other day had effected a lot of North facing terrain. Softer snow was avaiable in protectedd areas. Ridgetop winds, in the 20's were transporting, and loading North aspects while we were there.

Snowmobiles are getting into non-motorized areas...check the Winter Travel Map on closures before you head out.

  • 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 16- 20 miles per hour. Temperatures will be near 32 degrees at upper elevations, then falling to 23. A 40% chance of less than half an inch of snow is possible.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Tuesday Tuesday Night Wednesday
Weather: A 40 percent chance of snow before 11am. Cloudy, with a high near 33. Calm wind. Total daytime snow accumulation of less than a half inch possible. Snow likely, mainly after 11pm. Cloudy, with a temperature rising to around 30 by 3am. Calm wind. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible. Snow likely, mainly before 11am. Cloudy, with a high near 32. Calm wind. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible.
Temperatures: High 33 deg. F. Low of 30 deg. F. High 32 deg. F.
Wind direction: NA NA NA
Wind speed: calm Calm Calm
Expected snowfall: less than half an inch in. less than half inch in. less than half inch in.
Granite Mountain at 7700 feet.
  Tuesday Tuesday Night Wednesday
Weather: A 40 percent chance of snow before 11am. Cloudy, with a temperature rising to near 33 by 11am, then falling to around 23 during the remainder of the day. Breezy, with a south wind 16 to 20 mph. Total daytime snow accumulation of less than a half inch possible. Snow likely, mainly after 11pm. Cloudy, with a low around 23. South wind 13 to 17 mph. Chance of precipitation is 60%. New snow accumulation of around an inch possible. Snow likely, mainly before 11am. Cloudy, with a high near 30. South southwest wind around 10 mph. Chance of precipitation is 70%. New snow accumulation of less than one inch possible.
Temperatures: High 33-23 deg. F. Low of 23 deg. F. High 30 deg. F.
Wind direction: South South South-Southwest
Wind speed: 16-20 MPH 13-17 MPH 10 MPH
Expected snowfall: 1/2 in. 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.