THIS AVALANCHE ADVISORY EXPIRED ON March 14, 2016 @ 7:11 am
Avalanche Advisory published on March 13, 2016 @ 7:11 am
Issued by -
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Today the avalanche danger is MODERATE above 6,000 feet, and CONSIDERABLE in specific areas above 7,000 feet. Above 7,000 careful snowpack evaluation and conservative decision making will be important today if travelling on the north half of the compass. If wind and snow exceeds the forecasted amount today, the avalanche danger could quickly increase on all aspects above 6,000 feet. Below 6,000 feet the danger is LOW due to overnight temperatures freezing the top of the wet snowpack.

How to read the advisory


  • Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Wind Slab
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With new snow and winds 15-25 mph (possibly increasing to 25-35) out of the south-southwest, expect to see new wind slabs this morning and throughout the day ranging from soft and touchy to hard and stubborn on leeward aspects above 7,000 feet. Older harder wind slabs can also be found on these aspects below the new wind slabs. The older hard slabs are sitting on an 'upside down' snowpack in some areas due to low density snow that has had heavier snow fall on top of it, all of which is sitting on a buried crust (less than ideal). The combination of these different layers will make travel in areas above 7,000 feet on leeward aspects dangerous, evaluate the snowpack carefully before committing to any lines today or better yet keep off of windloaded/leeward slopes until the snowpack has had time to adjust to the stress of the new snow and wind. Cracking, 'whoomping', hollow/drum like snow, sculpted snow surface, pillows, and scouring are all signs of wind moving snow around and terrain choices should be made appropriately. Also, keep in mind with winds as forecasted, that slabs could be and will be building mid-slope. These are especially dangerous due to the fact that you will be in the middle of your ski line or hill climb before you realize what you have gotten yourself into.

Avalanche Problem 2: Storm Slab
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If the snow today comes without wind we could see storm slabs develop. However, the chances of today not being windy are slim. Due keep storm slabs in mind today if there is a lack of wind and/or the snow that is falling becomes denser than the snow it is sitting on...'upside down' as it is often referred to.

advisory discussion

Thanks to all the disabled veterans and volunteers that braved the less than ideal conditions yesterday for the annual Disabled Veterans Fun Run Snowmobile Ride. The PAC was honored to be invited to speak to the group about avalanche safety before the group headed out towards Burgdorf for a day of snowmobiling. Hats off to all the veterans and the volunteers who made this annual event a success!

recent observations

Yesterday was another wet and grey day. Light snow started late in the afternoon at and cold temps overnight helped to start stabilizing our wet snowpack below 7,000 feet. We had no new reports of human or natural triggered avalanches, this does not mean that the snowpack could not avalanche. Density changes and crusts are cause for concern in isolated areas throughout the advisory area. This combined with the current storm that is impacting the area could cause for the avalanche danger to ramp up quickly today if wind and snow exceed current forecast.

weather

The mountains around McCall picked up 2-4 inches of new snow overnight, with winds out of the south in the teens and gusting into the 20's. Today we are forecasted to receive another 2-6 inches with winds out of the south-southwest 15-25 mph and increasing to 25-35 this afternoon with gusts into the 40's. The brunt of this storm will impact our area later today and into tonight, with precipitation totals in the next 24 hours bringing another 8-14 inches of new snow to the mountains.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Sunday Sunday Night Monday
Weather: Snow showers likely before noon, then rain and snow showers likely. Cloudy, with a high near 38. South southeast wind 6 to 11 mph. Chance of precipitation is 70%. Total daytime snow accumulation of less than a half inch possible. Rain showers before midnight, then rain and snow showers likely. Some thunder is also possible. Low around 25. South wind 8 to 15 mph. Chance of precipitation is 90%. New snow accumulation of around an inch possible. Snow showers likely. Cloudy, with a high near 33. Southwest wind 9 to 14 mph. Chance of precipitation is 70%. New snow accumulation of 1 to 2 inches possible.
Temperatures: High 38 deg. F. Low 25 deg. F. High 33 deg. F.
Wind direction: South-southwest South Southwest
Wind speed: 6-11 8-15 9-14
Expected snowfall: Less than half an inch in. 1 in. 1-2 in.
Granite Mountain at 7700 feet.
  Sunday Sunday Night Monday
Weather: Snow showers. High near 37. Windy, with a south wind 16 to 21 mph increasing to 25 to 30 mph in the afternoon. Winds could gust as high as 41 mph. Chance of precipitation is 80%. Total daytime snow accumulation of 2 to 4 inches possible. Snow showers. Some thunder is also possible. Low around 19. Windy, with a south southwest wind 35 to 40 mph decreasing to 22 to 27 mph after midnight. Winds could gust as high as 55 mph. Chance of precipitation is 100%. New snow accumulation of 3 to 7 inches possible. Snow showers. High near 29. Breezy, with a west southwest wind 18 to 22 mph, with gusts as high as 31 mph. Chance of precipitation is 80%. New snow accumulation of 2 to 4 inches possible.
Temperatures: High 37 deg. F. Low 19 deg. F. High 29 deg. F.
Wind direction: South South-southwest west-southwest
Wind speed: 16-21 increasing to 25-35 gusting 40 35-40 decreasing to 22-27 gusts 55 18-22
Expected snowfall: 2-4 in. 3-7 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.