THIS AVALANCHE ADVISORY EXPIRED ON February 20, 2017 @ 6:19 am
Avalanche Advisory published on February 19, 2017 @ 6:19 am
Issued by Kent May - Payette Avalanche Center
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The avalanche danger is CONSIDERABLE above 7,000 feet today due to human triggered avalanches being likely. Winds out of the south over the last few days have caused wind slabs of up to two feet deep on all leeward slopes. Below 7,000 the danger is MODERATE and human triggered wind slabs avalanches, and in the lowest elevation loose wet avalanches, are possible.

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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With another windy day in the upper elevations wind slabs are our number one concern. Depending on location, you can find a few different generations of wind slabs that have developed over the last few days. The most suspect slopes today will be the ones with any north facing tilt due to the wind being primarily out of the south throughout this storm. However, as usual with wind, it is variable and be on the lookout for clues of wind loading on all slope in the upper elevations.

*The scary part about our current wind slab situation is the hard rain crust surface that these slabs are resting on. The crust is making for a less than ideal bond between it and the new snow and will likely avalanche on steep slopes under the weight and stress of a snowmachiner or skier.

Avalanche Problem 2: Storm Slab
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Over the last 24 hours we have gotten 2 to 10 inches of snow and today we will see another 3 to 10 inches of snow depending on location and elevations. In areas that were sheltered from the wind expect to find storm slabs today. These storm slabs will be quite tender and easy to trigger, especially on steep slopes. As with the wind slabs, we are concerned about the stout rain crust that the new snow is sitting on. The bond is poor, and snow will move on steep slopes.

Play it safe today and stick to low angle slopes and meadows and enjoy the powder.

advisory discussion

Snowmobiler/Snowbiker Travel Restrictions: 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").

 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 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.

recent observations

I toured out the Brundage ridge line yesterday during the storm. The visibility was poor due to blowing snow and I could not see any signs of natural avalanches. However, what I could see was rapidly loading snow and cornice growth on all north and northwest aspects. Small test cornices were easily triggered with a light kick, and in some cases sympathetically. I dug a pit at 7,750 feet on a northwest aspect and found a soft, but cohesive, wind slab. In my tests it lacked energy, but made a very clean shear from the 1 inch rain crust that it was resting on.

 

 

CURRENT CONDITIONS Today's Weather Observations From the Granite Weather Station at 7700 ft.:
0600 temperature: 24 deg. F.
Max. temperature in the last 24 hours: 28 deg. F.
Average wind direction during the last 24 hours: south
Average wind speed during the last 24 hours: 8.5 mph
Maximum wind gust in the last 24 hours: 24 mph
New snowfall in the last 24 hours: ~4 inches
Total snow depth: NA inches
weather

Today snow showers. Some thunder is also possible. High near 23. Breezy, with a south southwest wind 15 to 24 mph, with gusts as high as 33 mph. Chance of precipitation is 100%. New snow accumulation of 3 to 7 inches possible. Overnight forecasts are calling for another 2 to 4 inches and tomorrow another 5 to 9 inches. Happy Presidents' Day!

LONG TERM...Monday night through Sunday...Wet, southwest flow aloft Monday night through Tuesday should bring ample precip to the region, with snow levels near 6000 feet MSL. This moist flow shifts east on Wednesday as the trough off the Pacific Northwest shifts inland. Snow levels will drop to the valley floors by late Wednesday, but most of the moisture and precipitation will have shifted east by then. Still enough moisture to support snow showers Wednesday night and Thursday, but probably not enough to cause significant issues. Cooler temperatures should help to diminish flooding concerns after Wednesday. Models still handle pattern differently Friday through Sunday, but the general idea is to have a trough over the west, so kept temperatures relatively steady and below normal by about 5-10 degrees, with above normal chances for precip.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Sunday Sunday Night Monday
Weather: Rain and snow showers, becoming all snow after 11am. Some thunder is also possible. High near 36. South wind 7 to 11 mph. Chance of precipitation is 100%. Total daytime snow accumulation of less than one inch possible. A 50 percent chance of snow showers, mainly after 11pm. Cloudy, with a low around 28. South southeast wind 8 to 10 mph. New snow accumulation of around an inch possible. Rain and snow. High near 39. South wind 11 to 15 mph. Chance of precipitation is 100%. Little or no snow accumulation expected.
Temperatures: high 36 deg. F. low 28 deg. F. high 39 deg. F.
Wind direction: south south-southeast south
Wind speed: 7-11 8-10 11-15
Expected snowfall: Less than 1 in. 1 in. 0 in.
Granite Mountain at 7700 feet.
  Sunday Sunday Night Monday
Weather: Snow showers. Some thunder is also possible. High near 23. Breezy, with a south southwest wind 15 to 24 mph, with gusts as high as 33 mph. Chance of precipitation is 100%. Total daytime snow accumulation of 3 to 7 inches possible. Snow showers likely, mainly after 11pm. Cloudy, with a temperature rising to around 28 by 5am. Breezy, with a south southwest wind 17 to 21 mph. Chance of precipitation is 60%. New snow accumulation of 2 to 4 inches possible. Snow. High near 33. Windy, with a south southwest wind 28 to 30 mph, with gusts as high as 39 mph. Chance of precipitation is 100%. New snow accumulation of 5 to 9 inches possible.
Temperatures: high 23 deg. F. rising to 28 deg. F. high 33 deg. F.
Wind direction: south-southwest south-southwest south-southwest
Wind speed: 15-24 gusting 33 17-21 28-30 gusting 39
Expected snowfall: 3-7 in. 2-4 in. 5-9 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.