THIS AVALANCHE ADVISORY EXPIRED ON March 8, 2016 @ 6:59 am
Avalanche Advisory published on March 7, 2016 @ 6:59 am
Issued by George Halcom - Payette Avalanche Center
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The Avalanche Danger is Considerable above 7,000 feet on all aspects today on slopes over 35 degrees, especially upper elevation aspects that had areas of unconsolidated snow,  lingering wind slabs, buried crusts or heavily corniced ridgelines. Below 7,000 feet, the danger is Moderate. Rain fell up to 8,000 feet, it may  take a while for buried wet snow to re-freeze...Careful snowpack evaluation, cautious route finding, and conservative decision making are essential!

How to read the advisory


  • Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Wet Slab
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The rainline rose yesterday to nearly 8000 feet.  This may be the first time that layers in the snowpack get saturation from the rain, and there are plenty of crusts that may pool up water, and create a good lubrication for avalanches. Areas on northerly exposures that have large overhanging cornices will likely be tender...give these giants some room, and stay far back from the often hard to determine edge.

Other aspects that had older weak layers including crusts or grauple layers in the upper snowpack will likely be saturated enough to fail naturally or will already have failed last night.

It may  take a while for buried wet snow to re-freeze...Careful snowpack evaluation, cautious routefinding, and conservative decisionmaking are essential!

Avalanche Problem 2: Wind Slab
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Winds out of the South/ Southwest drove the last round of snow, sometimes reaching speeds of 41 mph. Expect to see some new, shallow wind slabs near ridge tops leading into NW, N. NE, and East aspects. The wind slabs should stabilize quickly as temperatures in the last 24 hours have trended downward, and are forecasted to do so over the next 24 hours. Cracking, hollow or drummy sounds, sculpting of the snow surface, thick pillows, and thin spots are all clues that should help you recognize wind slab problems.

weather

Light snow will fall in the upper elevations today bringing in olny around an inch with a high around 35 degrees, and moderate Southwest winds switching from the Northwest this afternoon. McCall will see a mixture of rain and snow this afternoon with a high around  40 degrees, West wind 5-7 mph. No new snow is expected tonight, and we should see low temps in the teens up high, and 20's in the valley. Wednesday we will begin  another warming trend.

 

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Monday Monday Night Tuesday
Weather: A slight chance of snow showers before 11am, then rain and snow showers likely. Cloudy, with a high near 40. Calm wind becoming west 5 to 7 mph in the afternoon. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible. A chance of rain and snow showers before 11pm, then a slight chance of snow showers. Cloudy, with a low around 23. West northwest wind 5 to 9 mph becoming calm after midnight. Chance of precipitation is 40%. New snow accumulation of less than a half inch possible. Increasing clouds, with a high near 38. Light and variable wind becoming south 5 to 10 mph in the afternoon.
Temperatures: 40 deg. F. 23 deg. F. 38 deg. F.
Wind direction: West W/NW South
Wind speed: 5-7 mph 5-9 mph becoming calm 5-10 mph
Expected snowfall: less than half in. less than half in. 0 in.
Granite Mountain at 7700 feet.
  Monday Monday Night Tuesday
Weather: Snow showers likely, mainly after 11am. Cloudy, with a high near 35. South southwest wind 5 to 15 mph becoming west northwest in the afternoon. Chance of precipitation is 70%. Total daytime snow accumulation of less than one inch possible. A 50 percent chance of snow showers. Cloudy, with a low around 19. North northeast wind 6 to 11 mph. New snow accumulation of less than one inch possible. Increasing clouds, with a high near 32. Light and variable wind becoming south 9 to 14 mph in the morning.
Temperatures: 35 deg. F. 19 deg. F. 32 deg. F.
Wind direction: S/SW N/NE Variable-South
Wind speed: 5-15 mph 6-11 mph 9-14 mph
Expected snowfall: less than one in. less than one 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.