THIS AVALANCHE ADVISORY EXPIRED ON March 3, 2016 @ 6:30 am
Avalanche Advisory published on March 2, 2016 @ 6:30 am
Issued by Dave Bingaman - Payette Avalanche Center
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The Avalanche Danger today is LOW today. Areas of concern exist on steep, upper elevation, leeward slopes especially on the north half of the compass where shallow wind slabs can still be found. Large cornices  have been failing with the warm temperatures for the last week and are triggerable with the added weight of a rider or a skier. Warming temperatures today and tonight will increase the wet/loose and wet slab potential over the next few days.

How to read the advisory


  • Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
Avalanche Problem 1: Wind Slab
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Older windslabs can still be found in upper elevations on leeward terrain. With not much snow left for transporting and warm temperatures, these slabs should be stabilizing and becoming less of a problem. Winds will pick up today, and into the evening tonight, transporting whatever new snow accumulates into leeward slopes creating a new crop of dense and potentially sensitive shallow windslabs. Keep an eye out for signs of freshly drifted or sculpted snow for the fresh wind slabs, and stiff snow with a chalky surface for the older wind slabs. 

 

Avalanche Problem 2: Cornice
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This winter has not had any shortage of snow, and most of the storms have been accompanaied by stout winds out of the South-Southwest. All of this wind and snow does a great job of forming large cornices on our ridgelines. The cornices on our ridges right now are large and overhanging and have been failing under their own weight with the warm temperatures over the last 10 days. They are also becoming extremely sensitive to added weight, and will break back farther than you think as pictured on this ridgeline near Storm Peak.

 

 

Avalanche Problem 3: Loose Wet
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Watch for an increase in Loose/Wet slide activity today as temperatures get close to 40 and stay there through the night tonight.  The amount of loose snow is pretty limited but as things warm up the snow will start to move, especially on the Southern aspects as intermittent sun heats things up even more. Roller balls, point releases and collapsing or unsupportable crusts are a good sign that the snow is warming quickly and it's time to move to a cooler aspect.

recent observations

Yesterday was another day of mixed precipitation with snow turning to rain in the valley.  Upper elevations got a light dusting of snow and grauple overnight with a series of passing Thunderstorms moving through early this morning. The snow should soften earlier today and will likely not refreeze tonight with a low near 40 at 7700 feet forecasted.

weather

Expect some fog in the valley this morning with scattered snow showers through the day in the mountains.  Above normal temperatures will be the theme today and through the weekend.  Gusty prefrontal winds out of the SW will accompany a series of low pressure systems that will push through Thursday evening and through the weekend. Accumulations will be light with a good chance for moderate accumulations(up to .5 inches of Snow Water Equivalent) beginning Friday night and through Sunday morning. Snow levels are expected to range from 5500-6500 feet with each wave of moisture.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Wednesday Wednesday Night Thursday
Weather: Isolated snow showers before 11am. Patchy fog before 11am. Otherwise, partly sunny, with a high near 42. South southwest wind 5 to 9 mph. Chance of precipitation is 20%. Mostly cloudy, with a low around 28. South wind 5 to 7 mph. A chance of rain showers before 11am, then rain and snow showers likely. Cloudy, with a high near 44. South southwest wind 6 to 8 mph. Chance of precipitation is 60%. Little or no snow accumulation expected.
Temperatures: 42 deg. F. 28 deg. F. 44 deg. F.
Wind direction: S/SW S S/SW
Wind speed: 5-9 5-7 6-8
Expected snowfall: Trace in. 0 in. Trace in.
Granite Mountain at 7700 feet.
  Wednesday Wednesday Night Thursday
Weather: Isolated snow showers before 11am. Partly sunny, with a high near 39. South southwest wind 10 to 17 mph. Chance of precipitation is 20%. Mostly cloudy, with a steady temperature around 40. Breezy, with a south southwest wind 16 to 26 mph, with gusts as high as 36 mph. Snow showers likely, mainly after 11am. Cloudy, with a high near 41. Breezy, with a southwest wind 21 to 25 mph, with gusts as high as 34 mph. Chance of precipitation is 70%. New snow accumulation of 1 to 2 inches possible.
Temperatures: 39 deg. F. 40 deg. F. 41 deg. F.
Wind direction: S/SW S/SW SW
Wind speed: 10-17 16-26, gusting to 36 21-25 gusting to34
Expected snowfall: Trace in. 0 in. 1-2 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.