Avalanche Advisory published on March 25, 2016 @ 7:24 am
Issued by Dave Bingaman - Payette Avalanche Center
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The Avalanche Danger is Considerable on steep, windloaded, northerly terrain today.  Strong winds out of the W/SW were easily transporting the new snow into the northern aspects yesterday and last night.  Expect to find new windslabs that will be reactive to the weight of a skier or snowmobile ranging in depth from a few inches up to a foot or more. The Avalanche Danger on non windloaded upper elevation slopes is Moderate, Low elevation slopes have Low Danger today.

How to read the advisory

  • Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Wind Slab
  • Character ?
  • Aspect/Elevation ?
  • Likelihood ?
    Very Likely
  • Size ?
    Very Large

Windslab continues to be our biggest concern today.  We observed widespread wind transport of the new snow yesterday as winds ramped up in the afternoon and swirled from the SW to the W through the day.  Expect to find new and sensitive windslabs on upper elevations, E, NE, N and NW slopes today. Given the velocity of the winds and the light snow being transported, you can expect to find wind deposited snow much further below the ridges than we have seen over the last few days of relatively light winds.  Expect to see pillows, spindrift cones and other tell tale signs of wind blown snow below steep or rocky headwalls and lower down in northerly terrain than normal. By yesterday afternoon, we were able to ski cut the freshly formed slabs on steep leeward terrain to a depth of about 6 inches. You can expect to find shallow and deeper(possibly over 2 feet?) windslabs throughout the north country depending on the windward snow fetches and the size of the deposition area or catchment. Look for tell tale visual clues and don't ignore cracking or hollow feeling snow beneath your skis or sled today.

recent observations

We toured around on the Western edge of Squaw Point yesterday and had a fully mixed bag of weather and snow conditions. Early in the day clouds and blowing snow kept visibility at a minimum and accumulated the forecasted 1-3 inches of snow before 1 pm. In the afternoon the winds kicked it up a notch and we had a break in the clouds that gave us a great view of the local peaks and the deep snowpack on all of our Northerly terrain.  We also obsereved high winds buffeting the peaks and snow plumes stretching quite a way down wind of the peaks.  We even saw a unique and quite large snow devil working up a ridgeline in upper French Creek.  These strong winds did a great job covering our tracks in a small NW bowl and instantly creating thin(but growing quickly) reactive wind slabs on all leeward features. Everywhere we looked we were amazed at the size and amount of cornices overhanging ridges and bowls, and even mid elevation sub-ridges and smaller terrain features. It has truly been a windy winter. The upper 18 inches of the snowpack above last weekend's melt freeze crust looked very good and has begun to consolidate from the crust up providing pretty good stability in the new snow we got this week. Below the crust there are still some weak layers preserved that may linger through the end of the season.  These deeper layers will likely continue to be hard to trigger until we see another major warmup.


Today is going to bring another 1-3 inches of snow to the West Central Mountains with temperatures close to normal.  A cold front tonight will drop temperatures down into the low teens tonight.  Winds will be light to moderate in the upper elevations today out of the West then shifting around to the Northwest as the cold front enters the area later in the afternoon or early evening,  Another pulse of moisture is headed our way on Sunday with the chance of more precipitation through the early part of next week.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Friday Friday Night Saturday
Weather: Snow showers likely, mainly after noon. Some thunder is also possible. Cloudy, with a high near 36. Calm wind becoming northwest 5 to 7 mph in the afternoon. Chance of precipitation is 60%. Total daytime snow accumulation of less than one inch possible. Partly cloudy, with a low around 16. North northwest wind around 6 mph becoming calm in the evening. Mostly sunny, with a high near 41. Calm wind becoming south 5 to 7 mph in the afternoon.
Temperatures: 36 deg. F. 16 deg. F. 41 deg. F.
Wind direction: Calm then NW N/NW S
Wind speed: 5-7 6 5-7
Expected snowfall: Trace in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Friday Friday Night Saturday
Weather: Snow showers. Some thunder is also possible. High near 31. West wind 6 to 11 mph. Chance of precipitation is 100%. Total daytime snow accumulation of 1 to 3 inches possible. A 20 percent chance of snow showers before midnight. Mostly cloudy, with a low around 15. North wind 6 to 11 mph becoming light northeast after midnight. Mostly sunny, with a high near 37. Light southwest wind becoming south 10 to 15 mph in the morning.
Temperatures: 31 deg. F. 15 deg. F. 37 deg. F.
Wind direction: W N SW becoming S
Wind speed: 6-11 6-11 10-15
Expected snowfall: 1-3 in. 0 in. 0 in.

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.