THIS AVALANCHE ADVISORY EXPIRED ON March 20, 2016 @ 7:00 am
Avalanche Advisory published on March 19, 2016 @ 7:00 am
Issued by Dave Bingaman - Payette Avalanche Center
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The Avalanche Danger today is Moderate throughout the West Central Mountains.  Daytime temperatures near 50 degrees will make the possibility of loose avalanches on steep, sunny slopes increase as the snowpack begins to warm.  Skiers or snowmobilers may also be able to trigger some remaining wind slabs on steep windloaded northerly terrain. Below 6000 feet, the danger is Low do to less new snow during the last storm cycle. 

How to read the advisory


  • Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Loose Wet
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We have been seeing some small, loose dry and loose wet slides and increasing roller ball activity on steep terrain over the last few days as the new snow started warming.  Pay attention today as the snowpack warms quickly on the solar aspects. Todays high temperature is going to be 10-12 degrees warmer than the last few days.  Increasing roller ball activity is a sign of a warming snowpack and also a sign to avoid steep sun affected slopes. East facing slopes still hold the potential to release loose, dry and loose, wet avalanches as the morning sun heats the remaining new, soft snow up. Cornices should also be avoided right now as well. Large cornices will begin to fail as temperatures increase.  Travel on or below cornices is not recommended as the day warms.

Avalanche Problem 2: Wind Slab
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We are still seeing a lingering wind slab problem on steep, windloaded terrain.  The winds that accompanied the beginning of last week's storms transported a lot of snow.  Some of the windslabs are very dense and unlikely to be triggered right now but Wednesday and Thursday we were still seeing some areas of hollow or punchy windslab that was resting on loose, unconsolidated snow below.  Windslabs between a few inches and up to about 20 inches are still a concern if you are playing in the shady, northerly terrain. Your best bet for staying safe is to utilize good travel and play/riding techniques with only 1 person on a slope at a time. Keep your eyes on your partners if you are playing in the windloaded terrain and plan for an exit route if you do trigger one of  these windslabs. Large cornices should also be avoided as they have been breaking surprisingly big since last weekend and the warm temperatures are likely to make some of these fail naturally in the heat of the day.

recent observations

The  snowpack continued to warm gradually yesterday, day time temperatures did not rise quickly but the snowpack has continued to warm over the last few days.  If you are looking for soft snow today, you are going to be looking at shady, north aspects.  Bear in mind that we have been seeing some lingering, shallow windslabs near the ridges in these areas leftover from last weekend's  gusty winds.  We saw a few more roller balls yesterday and small point release, loose slides were on the increase as well. Watch for increasing loose, wet activity on the solar aspects as the sun starts warming the East aspects this morning and wrapping around the South half of the compass later in the day.  A variety of crusts will be waiting for you if you are on these slopes early in the day.

 

 

weather

The ridge of high pressure is firmly established today with spring like temperatures throughout the area. Look for high temperatures near 50 in both the upper and lower elevations. With plenty of sun today it is likely to feel warmer than the forecasted 46 degrees. South winds will be steady near the ridges around 10 mph today.  Low tonight will be 32 in the mountains and around 25 in the valleys. A low pressure system will bring increasing clouds Sunday with rain showers to 8000 feet by Sunday night. The long term forecast calls for falling snowlines Monday and Tuesday with a few inches of snow each day and snow showers remaining possible through the end of the week.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Saturday Saturday Night Sunday
Weather: Sunny, with a high near 46. Calm wind becoming south around 5 mph in the afternoon. Mostly clear, with a low around 25. Light and variable wind. Mostly sunny, with a high near 49. Calm wind becoming south 5 to 8 mph in the afternoon.
Temperatures: 46 deg. F. 25 deg. F. 49 deg. F.
Wind direction: S Variable S
Wind speed: 5 Light 5-8
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Saturday Saturday Night Sunday
Weather: Sunny, with a high near 46. South wind around 10 mph. Mostly clear, with a low around 32. South wind 11 to 15 mph. A slight chance of rain and snow showers after noon. Mostly sunny, with a high near 46. Breezy, with a south wind 17 to 21 mph. Chance of precipitation is 20%.
Temperatures: 46 deg. F. 32 deg. F. 46 deg. F.
Wind direction: S S S
Wind speed: 10 11-15 17-21
Expected snowfall: 0 in. 0 in. Trace/Rain 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.