THIS AVALANCHE ADVISORY EXPIRED ON January 17, 2017 @ 6:51 am
Avalanche Advisory published on January 16, 2017 @ 6:51 am
Issued by Dave Bingaman - Payette Avalanche Center
bottom line

The Avalanche Danger is MODERATE on wind loaded, slopes above 7000 feet. Wind slabs remain a concern on upper elevation slopes with recent natural avalanches and the potential for human triggered slabs between a few inches and a few feet thick.  Small, loose snow avalanches are also possible and may provide the trigger for larger slab avalanches especially as direct sun and afternoon warming affect the 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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The wind slab problem is fairly widespread on the Northern half of the compass above 7000 feet.  While these slabs are becoming less touchy over time some of these slabs are resting on a variety of old snow surfaces ranging from hard wind board to loose, faceted snow.  You are likely to trigger these slabs not only at the ridgelines but in steep terrain below rock faces, in gullies or other confined terrain where the wind blown snow accumulated. Within the last week we have been able to intentionally trigger these slabs and last weekend skiers on Sawtooth Peak unintentionally triggered several small wind slabs.

Over the last week we have toured and traveled into some of the steepest northerly terrain and found wind slab crowns scattered across these slopes. What we also noticed is that most of these slopes that did not run on their own are still untouched by sledders or skiers still so no artificial/ human triggers have been applied yet.  

Overall, you can look at windloaded terrain right now with the great visibility and see the warning signs: rounded, pillowy, sculpted terrain is the norm throughout the Northerly terrain, and these features are easy to recognize clues of where the problem areas are right now. Play it safe and stick to lower angle terrain, or terrain that has not been affected by the wind while these slabs continue to gain stability.  Remember right now, just because you are not seeing recent avalanches on some steep northerly terrain does not mean those slopes are safe...

Avalanche Problem 2: Loose Wet
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With a strong inversion in place, upper elevation temperatures will be climbing to above freezing today.  The combined effects of the sun and the warmest day of the week will put some new stresses on the snowpack today.  Over the last few days, we saw signs of change in the snowpack on the southerly or solar aspects: thin melt/freeze crusts have formed  in some areas, roller balls and small, loose avalanche activity increasing as the day warmed and trees shedding snow and rime at the same time.  Today should be a mirror image of the last  few days and as the warming starts, watch for an increase in the potential of loose wet slides later in the day. You can see quite a few small point release slides on sunny, rocky terrain right now.  The biggest concern would be if you got pushed around in areas with bad consequences by these small slides.  You should also be aware that as the bonds in the snowpack are stressed, these small slides may step down into deeper layers triggering a larger slab avalanche.

advisory discussion

Snowmobiler/Snowbiker Travel Restrictions:  a quick reminder that the Granite Mountain Area Closure is now in effect.  In addition there are other areas on the Payette National Forest that are CLOSED to snowmobile traffic including Jughandle Mt east of Jug Meadows, Lick Creek/Lake Fork Drainage (on the right side of the road as you are traveling up canyon), and the area north of Brundage Mt Ski area to junction "V" and along the east side of Brundage snd Sargeant's Mts. with the exception of the Lookout Rd( junction "S").  Please respect these closures and other users recreating in them.  Winter Travel Map(East side)

There is still room in the Sawtooth Avalanche Center's Motorized Level 1 avalanche class in Fairfield next weekend.  You can email them at info@sawtoothavalanche.com for more information or to sign up, stop making excuses.  This is a great class, reasonably priced  with a shortened classroom session and 2 field days jam packed with useful travel, rescue and decision making information.

Remember your information can save lives. If you see anything we should know about, please participate in the creation of our own community avalanche advisory by submitting snow and avalanche conditions. It's okay if you leave some fields blank, just fill out what you know and/or submit photos. You can  also email us at  forecast@payetteavalanche.org.

The Friends of the Payette Avalanche Center (FPAC) needs YOU! We are in desperate need of more user support and financial assistance. The avalanche forecast is not a guaranteed service, and is in jeopardy of dwindling down to only a couple of days a week in the near future. Please help if you can by clicking the DONATE tab above. If you value this life saving information, make a donation or help the FPAC in raising funds for the 

recent observations

Problem layers are growing and so are the precipitation forecasts for the next round of storms entering our areas beginning Tuesday.  Well developed Surface Hoar and widespread development of Near Surface Facets are going to be a MAJOR concern as snow accumulates above them.  Buried Surface Hoar is Public Enemy number one in the avalanche world, this fragile layer when buried is responsible for more avalanche accidents and deaths than any other type of problem.

 

 

 

weather

SHORT TERM...Today through Tuesday... Continue dry and cold with upper ridge passing through and maintaining the surface-based inversion through early Tuesday. Ridge will shift southeast out of our CWA tonight allowing moist westerly Pacific air to flow inland. Light snow will start in Baker County Tuesday afternoon, a little later than previous model timing. Models also seem to be warming the surface and raising the snow level too fast Tuesday. The Snake River Basin has fewer clouds this night and is therefore colder than last night. But areas of fog and stratus will still be able to produce flurries through the morning.  

LONG TERM...Tuesday night through Monday...The first in a series of Pacific weather systems will spread precipitation across our CWA Tuesday night, mainly as snow. Precipitation will be widespread Wednesday and Wednesday night. Although models forecast rising snow levels, it is uncertain how soon the cold air will mix out of the lower valleys. Models show a very stable boundary layer, especially in the Snake River Valley, through Thursday morning, due to warming aloft. So precipitation in the lower valleys could continue as snow, or a mix of snow and freezing rain, at least until Thursday afternoon. However, by that time snow levels will be lowering as a weakening upper level trough moves inland. After a brief break Thursday night, a colder north Pacific system will bring snow at all elevations Friday through Saturday, followed by yet another system on Monday. Temperatures will average around 5 degrees below normal Wednesday and Thursday, and around 10 degrees below normal Friday through Monday.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Monday Monday Night Tuesday
Weather: Patchy Fog otherwise mostly sunny. Fog in the valleys and mostly clear. Patchy fog in the am then increasing clouds.
Temperatures: 16 deg. F. -2 deg. F. 20 deg. F.
Wind direction: S S S
Wind speed: Up to 5 Around 6 3-6
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Monday Monday Night Tuesday
Weather: Sunny Mostly clear Increasing Clouds
Temperatures: 32 deg. F. 18 deg. F. 30 deg. F.
Wind direction: W SW SW
Wind speed: 5-7 11-18 16-20
Expected snowfall: 0 in. 0 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.