THIS AVALANCHE ADVISORY EXPIRED ON March 15, 2016 @ 6:17 am
Avalanche Advisory published on March 14, 2016 @ 6:17 am
Issued by -
bottom line

The avalanche danger is CONSIDERABLE at elevations above 7,000'. Today skiers and riders are likely to trigger windslabs in steep, exposed terrain. In steep and sheltered terrain storm slabs and loose dry avalanches will be your main concern and human trigger will be likely. At mid elevations the danger is MODERATE and below 6,000' the danger is LOW due to less wind and snow.

How to read the advisory


  • Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Wind Slab
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Yesterdays strong south-southwest winds combined with moderate snowfall are enough to be a cause for concern today. Cautious and conservative decision making and route finding will be the key to staying safe today in the mountains. Multiple different generations of windslabs are making up the top 5-30" of our snowpack and will range from touchy in less exposed areas to stubborn on more exposed and wind affected slopes. Fresh wind slabs will be developing throughout the day today as well. Keep an eye out for active wind loading, and inspect all slopes before committing to them. Also, all cornices are suspect right now due to the recent wind events. Keep far back from all ridgelines with cornices, especially ones over consequential terrain.

Avalanche Problem 2: Storm Slab
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Storm slabs have trouble forming during storms that have moderate to strong winds. However, if you are traveling in steep terrain today that was/is sheltered from the wind use caution due to these slabs being at their prime. The new snow is resting on a wide variation of surfaces including old wind slabs and crusts. If you were to trigger a storm slab it will most likely start small, but could entrain more snow and carry you someplace you don't want to be (cliffs, rocks, trees, creeks, etc.).

advisory discussion

Don't let powder fever override your knowledge of avalanches and our snowpack. Good riding conditions will be found today on low angle slopes that were not exposed to the high winds and the resulting layers of wind slabs. Give the snowpack some time to adjust to this new load of snow and wind and keep safe. In low elevations below 6,000' watch for boot penetration due to the wet snowpack that we had prior to the past two days of freezing temps. The crust that formed over the wet snowpack is thin, and if you are sinking into the wet snow more than boot top deep it could mean trouble on any steep slopes due to wet slabs still being a concern...

recent observations

Tamarack Ski Patrol reported large cornice avalanches with explosives in the morning and affective and productive cornice 'stomping' through the day and afternoon due to the strong south-southwest winds. Also, due to the strong winds and moderate snowfall pillows of wind deposited snow were developing 8-16" deep below the ridgelines on SE-NE facing aspects. In the north half of the advisory area strong winds were also reported with shallow wind slabs being the result.

weather

Well...we got snow and wind, but the major precipitation went south of the advisory area. The mountains around McCall picked up 8-12" on new snow yesterday that equaled over 1" of snow water equivalent. The winds were moderate to strong out of the south-southwest. Today we are forecasted to receive another 2-4" of new snow with winds out of the west-southwest 17-22 mph.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Monday Monday Night Tuesday
Weather: Snow showers. Some thunder is also possible. High near 34. South southwest wind 9 to 11 mph. Chance of precipitation is 80%. Total daytime snow accumulation of 1 to 2 inches possible. Snow showers likely. Cloudy, with a low around 20. Southwest wind 5 to 8 mph. Chance of precipitation is 70%. New snow accumulation of around an inch possible. Snow showers likely. Cloudy, with a high near 33. Southwest wind 5 to 7 mph. Chance of precipitation is 60%. New snow accumulation of less than one inch possible.
Temperatures: High 34 deg. F. Low 20 deg. F. High 33 deg. F.
Wind direction: south-southwest southwest southwest
Wind speed: 9-11 5-8 5-7
Expected snowfall: 1-2 in. 1 in. Less than one inch in.
Granite Mountain at 7700 feet.
  Monday Monday Night Tuesday
Weather: Snow showers. Some thunder is also possible. High near 28. Breezy, with a west southwest wind 17 to 22 mph. Chance of precipitation is 90%. New snow accumulation of 2 to 4 inches possible. Snow showers. Low around 14. West wind around 17 mph. Chance of precipitation is 90%. New snow accumulation of 1 to 3 inches possible. Snow showers. High near 26. Wind chill values between -1 and 9. West southwest wind 11 to 17 mph. Chance of precipitation is 100%. New snow accumulation of 2 to 4 inches possible.
Temperatures: High 28 deg. F. Low 14 deg. F. High 26 deg. F.
Wind direction: west-southwest west west-southwest
Wind speed: 17-22 around 17 11-17
Expected snowfall: 2-4 in. 1-3 in. 2-4 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.