THIS AVALANCHE ADVISORY EXPIRED ON March 10, 2016 @ 7:05 am
Avalanche Advisory published on March 9, 2016 @ 7:05 am
Issued by Dave Bingaman - Payette Avalanche Center
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The Avalanche Danger is Moderate today on slopes over 35 degrees.  A combination of lingering wind slabs and large cornices will require caution on steep E,NE, N and NW slopes. Steep South, East and West facing slopes will see an increase in loose/wet avalanche activity as the temperatures begin to rise today especially if the clouds break and the sun makes even a brief appearance later in the day. Rain overnight and warming temperatures will increase the avalanche hazard tomorrow.

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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The rain line rose Sunday to above 7,000 feet. The new snow (4-6") is resting on a crust (below that crust, below 7,500 ft the snow is still mostly saturated)  that formed last weekend.  The added stress of heat and direct sunlight will increase the possibility of loose/wet avalanches on the Southerly terrain and on windloaded East aspects..  With the temperatures rising over the next few day, it will likely take awhile for the snow below the surface to refreeze. If you see signs of an overheating snow pack, like roller balls, point releases, which usually start near rocky outcrops, or are sinking into the snow above your boot tops, move to a cooler aspect.

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. We found some of these wind slabs yesterday in NW terrain near the ridges where they were sitting above a layer of cold, unconsolidated snow that didn't get the soaking from last weekend's rain.  We stomped around on them but could not get them to fail deeper than the shallow layer of new snow. We can expect a repeat of last week's storm over the next few days with increasing winds, and a warm front accompanied by a moist SW flow. 

recent observations

We toured around Boulder Mountain yesterday and found a rapidly warming snowpack on the E, S and SW aspects.  We saw several decent sized point releases on steep East Facing slopes that were just beginning to heat up and lose cohesion. One of these entrained a decent amount of snow and left debris piles on trees below it.  We also had a good sized point release or loose/wet slide reported by Brundage Cat Ski in Wong's Bowl yesterday.  Most of these areas had just enough new snow (3-5 inches) on a slick crust that once the snow surface begins to warm up the unconsolidated snow is able to move pretty easily on top of the crust.

We also observed some cracking on protected northerly terrain where shallow wind slabs were left over from last weeks gusty winds. The rain crust from last week is evident on most aspects below the new snow and is providing a slick interface for the new snow and the isolated wind slabs. The sunny aspects developed a thin melt freeze crust yesterday as the clouds came back in later in the day. Great skiing and riding can be found in sun protected areas but use a little bit of caution and safe travel techniques as you search out the remaining powder stashes.  

 

        

 

weather

The West Central picked up about an inch of new snow overnight, today look for mostly cloudy skies with a chance of scattered snow showers throughout the afternoon. Temperatures will be rising tonight as a warm front and the first in a series of small storms enters the West Central.  The front will also be accompanied by increasing S/SW winds with gusts to 46 overnight. Over the next few days we will see snowlines pushing back up towards 7000 feet with a few inches of snow each day for the rest of the week.  The precipitation will be mostly rain in the valleys. The weekend will bring back freezing temperatures at night and a decrease in the chance of precipitation.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Wednesday Wednesday Night Thursday
Weather: A slight chance of snow before 11am, then a chance of rain and snow. Cloudy, with a high near 38. Calm wind becoming south southeast 5 to 9 mph in the afternoon. Chance of precipitation is 30%. Total daytime snow accumulation of less than a half inch possible. Rain and snow likely, becoming all rain after 11pm. Cloudy, with a low around 34. South southeast wind 6 to 9 mph. Chance of precipitation is 70%. Little or no snow accumulation expected. Rain. High near 45. South southeast wind around 10 mph. Chance of precipitation is 80%
Temperatures: 38 deg. F. 34 deg. F. 45 deg. F.
Wind direction: SE SE SE
Wind speed: 5-9 6-9 10
Expected snowfall: Trace in. 0 in. Rain in.
Granite Mountain at 7700 feet.
  Wednesday Wednesday Night Thursday
Weather: A 40 percent chance of snow, mainly after 11am. Cloudy, with a high near 35. South wind 5 to 10 mph increasing to 13 to 18 mph in the afternoon. Total daytime snow accumulation of less than a half inch possible. Snow. Temperature rising to around 41 by 3am. Windy, with a south southwest wind 22 to 32 mph, with gusts as high as 46 mph. Chance of precipitation is 80%. New snow accumulation of less than one inch possible. Snow. High near 42. Windy, with a south wind 28 to 33 mph, with gusts as high as 47 mph. Chance of precipitation is 90%. New snow accumulation of 1 to 2 inches possible.
Temperatures: 35 deg. F. 41 by 3am deg. F. 42 deg. F.
Wind direction: S S/SW S
Wind speed: 5-10, increasing later in the day 22-32, gusting to 46 28-33, gusting to 47
Expected snowfall: Trace in. Trace 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.