THIS AVALANCHE ADVISORY EXPIRED ON February 24, 2017 @ 5:33 am
Avalanche Advisory published on February 23, 2017 @ 5:33 am
Issued by George Halcom - Payette Avalanche Center
bottom line

The avalanche danger is CONSIDERABLE above 7,000 feet. Snow and strong winds from around the compass have created slabs in exposed and sheltered terrain on multiple aspects. Multiple generations of wind slabs may be sensitive to the weight of skiers and riders, may be up to 3’ thick, and have formed on top of a variety of surfaces.  Below 7,000 feet the avalanche danger is MODERATE.

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 ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Winds upwards of 26 MPH from around the Northern end of the compass are taking their turn now over the last 24 hours at pushing, and moving snow which have formed a new crop of wind slabs. Winds out of the West-Southwest, along with colder, then warmer snow did a good  this past week of forming a dense slab that was resting on some facets on top of about an inch of snow on top of a rain crust that was the bedsurface for many recent natural avalanches. A heavier, slabby layer formed, and is now lies beneath 6-12 inches of light density snow. The winds were very strong during the last couple days, knocking mature trees over, and producing natural and human triggered slab avalanches up to 3 feet deep in various locations on North Aspects around the advisory area.

 

 

advisory discussion

Snowmobiler/Snowbiker Travel Restrictions: Please respect these closures and other users recreating in them.  Winter Travel Map(East side). You can download the map to the AVENZA app on your phone, and know your exact location while you are out riding.  It is your responsiblity to know where closures exist on the forest.

The Granite Mountain Area Closure is in effect Jan15-March 15, please respect Snowcats operating in this and nearby areas.  In addition there are other areas on the Payette National Forest that are CLOSED to snowmobile traffic including Jughandle Mt east of Jug Meadows,North of Boulder Mtn, East of Rapid Peak,  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 and Sergeants' Mts. with the exception of the Lookout Rd( junction "S").

 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 future.

We rely on our snowmobiles to bring you quality forecasts. Currently two of our sleds have nearly 8,000 miles on them. We need your help raising funds for replacements! Please contact us if you can help in any way forecast@payetteavalanche.org or click DONATE tab.

recent observations

Tuesday, Brundage Catski reported a natural slab avalanche up to 3 feet deep Granite Mountain's Baby Face (NNE 7200ft).  Check out the observation in our observations section, where othe skiers and riders have reported triggering similar slides over the last couple of days.

Yesterday, we went out to look at the natural avalanche on Granites Baby Face. The Sun came out briefly and it was very warm, luckily it went away quickly. We found a fairly hard wind slab 3-4 feet deep that released on facets that formed on top an inch or so of denser snow that came in wet and stuck very well to the rain crust that formed. within the 3-4 feet, we found a couple layers in the upper 2 feet that are still working on bonding and are showing some strength. Skiing and snowmobiling was good, and fairly effortless.

.

Above is a snapshot of the Crown yesterday.

 

 

CURRENT CONDITIONS Today's Weather Observations From the Granite Weather Station at 7700 ft.:
0600 temperature: 11 deg. F.
Max. temperature in the last 24 hours: 25 deg. F.
Average wind direction during the last 24 hours: Northeast
Average wind speed during the last 24 hours: 15 mph
Maximum wind gust in the last 24 hours: 30 mph
New snowfall in the last 24 hours: NA inches
Total snow depth: NA inches
weather

TODAY a 40 percent chance of snow showers. Cloudy, with a high near 20. Wind chill values between -5 and 5. Blustery, with a north wind 18 to 21 mph. New snow accumulation of 1 to 2 inches possible.

LONG TERM...Friday night through Wednesday...Cold active weather pattern will continue through Tuesday with the passage of two upper level troughs. Models remain consistent in keeping the first trough on Friday night into Saturday well off the west coast with the forecast area remaining largely unaffected. Showers could develop over the higher terrain Saturday afternoon but snow accumulations will be little if any. This trough weakens as it shifts southeast across California Saturday night. A second stronger and more moisture trough moves along the coast Sunday before shifting inland late Monday into Tuesday. Models still don`t have a great handle on this system and differ with how far south the trough drops Monday before moving inland. This mainly has implications with the extent of shower coverage Sunday afternoon through Monday. Northwesterly flow will continue the changes for snow showers on Tuesday. Snow amounts will be light with a few inches in the mountains to little if any accumulations in the valley as the ground and surface temperatures remain at or above freezing Sunday through Monday. Upper level ridge begins to build along the west coast Wednesday and remaining through the weekend. It`s not particularly strong but it will keep the area dry with temperatures climbing back to seasonal normals by Thursday.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Thursday Thursday Night Friday
Weather: A 30 percent chance of snow showers. Cloudy, with a high near 28. North northwest wind 9 to 14 mph. New snow accumulation of less than a half inch possible. A 30 percent chance of snow showers, mainly after midnight. Cloudy, with a low around 12. Northwest wind 7 to 11 mph. New snow accumulation of less than a half inch possible. A 20 percent chance of snow showers. Cloudy, with a high near 27. North northwest wind around 5 mph becoming calm in the morning.
Temperatures: high 28 deg. F. low 12 deg. F. high 27 deg. F.
Wind direction: north-northwest northwest north-northwest
Wind speed: 9-14 7-11 5-calm
Expected snowfall: less than one half in. less than one half in. 0 in.
Granite Mountain at 7700 feet.
  Thursday Thursday Night Friday
Weather: A 40 percent chance of snow showers. Cloudy, with a high near 20. Wind chill values between -5 and 5. Blustery, with a north wind 18 to 21 mph. New snow accumulation of 1 to 2 inches possible. Scattered snow showers. Cloudy, with a low around 8. Wind chill values between -1 and -7. Blustery, with a north wind 13 to 21 mph. Chance of precipitation is 30%. New snow accumulation of less than one inch possible. A 20 percent chance of snow showers. Mostly cloudy, with a high near 21. Wind chill values between -5 and 5. North wind 5 to 9 mph becoming calm in the morning.
Temperatures: 20 deg. F. low 8 deg. F. high 21 deg. F.
Wind direction: north north north
Wind speed: 18-21 13-21 5-9
Expected snowfall: 1-2 in. less than one 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.