THIS AVALANCHE ADVISORY EXPIRED ON March 4, 2016 @ 6:01 pm
Avalanche Advisory published on March 4, 2016 @ 6:01 am
Issued by George Halcom - Payette Avalanche Center
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The Avalanche Danger today remains LOW today. Sustained warm temperatures will prolong the wet/loose and wet slab potential through Friday. Areas of concern exist on steep, upper elevation, leeward slopes especially on the North half of the compass where large, overhanging 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. Shallow wind slabs can still be found near ridge lines leading into leeward/Northern aspects.

How to read the advisory


  • Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
Avalanche Problem 1: Loose Wet
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Loose/Wet slide potential remains today as temperatures overnight hovered near, and above freezing. The high temperature in the mountains should reach 44 degrees this afternoon.  The amount of loose snow is pretty limited, but a skier or rider could easily get a wet slide going in terrain steeper than 35 degrees. 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.

 

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 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 on Monday.

 

 

Avalanche Problem 3: 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 calm down tonight, transporting whatever little new snow accumulates into leeward slopes creating a new crop of shallow, dense and potentially sensitive 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. 

recent observations

Above freezing temperatures have dominated the last 24 hours with a low temperature last night at Secesch Summit (6500 feet) of only 31 degrees for an hour. 

weather

Warm temperatures are forecasted to persist through Friday evening when the snow line should come down from 7500 feet to 4500 feet by Sunday night. Today, expect to see similar warm high temperatures reaching around 44 in the valley, and 41 in the upper elevations. Winds will be greatest in the upper elevations out of the Southwest 16-21 Mph, with gusts up to 37 Mph. Not much new snow is forecasted until Saturday. Today we will receive just under an inch in the upper elevations, and little to no new snow in the Long Valley. Temperatures overnight should dip just a few degrees below freezing.

 

 

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Friday Friday Night Saturday
Weather: Showers, mainly after 11am. High near 44. South southeast wind 6 to 8 mph. Chance of precipitation is 80%. A 20 percent chance of showers before 11pm. Partly cloudy, with a low around 24. Calm wind becoming east southeast around 5 mph in the evening. A 20 percent chance of showers after 11am. Partly sunny, with a high near 47. East wind 6 to 9 mph becoming south southwest in the afternoon.
Temperatures: 44 deg. F. 24 deg. F. 47 deg. F.
Wind direction: S/SE E/SE E
Wind speed: 6-8 5 6-9
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Friday Friday Night Saturday
Weather: Snow showers, mainly after 11am. High near 41. Breezy, with a southwest wind 23 to 28 mph decreasing to 16 to 21 mph in the afternoon. Winds could gust as high as 37 mph. Chance of precipitation is 80%. New snow accumulation of less than one inch possible. A 30 percent chance of snow showers before 11pm. Partly cloudy, with a low around 28. West southwest wind 8 to 10 mph. New snow accumulation of less than a half inch possible. Partly sunny, with a high near 43. Breezy, with a south southwest wind 11 to 20 mph.
Temperatures: 41 deg. F. 28 deg. F. 43 deg. F.
Wind direction: SW W/SW S/SW
Wind speed: 16-21 Gusts to 37 Mph 8-10 11-20
Expected snowfall: less than one in. less than one half 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.