THIS AVALANCHE ADVISORY EXPIRED ON February 2, 2017 @ 6:35 am
Avalanche Advisory published on February 1, 2017 @ 6:35 am
Issued by George Halcom - Payette Avalanche Center
bottom line

The avalanche danger today is MODERATE on steep, wind affected slopes above 7000 feet due to human triggered avalanches being possible. Below 7000 feet the avalanche danger is LOW.  Do keep in mind that a layer of buried surface hoar is still being tracked around the advisory area. While the chances of triggering an avalanche due to this problem is low, the consequences would be high.

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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  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
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Winds this mprning have calmed down, but moderate winds gusting upwards of 24MPH out of theSouth-southwest over the last 24 hours, and a few new inches of snow have helped form newer wind slabs up to 6 inches thick in the upper most terrain on the north half of the compass. These new wind slabs may be resting on a slick crust that has developed in the last week from the Sun, and may be sensitive to the weight of a skier or rider. Be cautious in steep exposed terrain, where a small wind slab could knock you off your feet.

Older wind slabs can still be found, but should be very stubborn to trigger. However, once triggered any avalanche can grow into a bigger problem if it breaks into weaker snow. Your best strategy is to simply avoid fat looking, rounded pillows of snow, especially if they feel or sound hollow like a drum.

advisory discussion

We are still tracking buried surface hoar and near surface facets that are now buried in our snowpack. These persistent grain types can awaken after being dormant for an extended period of time (hence the name persistent). While we don't have them as an avalanche problem, keep this layer in mind as you make your travel plans for the day. The layer is most likely to be found on any slopes with a north tilt to them, in middle and upper elevations. Areas to be especially weary of are those that were not impacted by the winds (sheltered) previous to our last big load of snow.

**Before committing to skiing or riding a slope over 30 degrees on the north half of the compass today, take a moment to dig into the snow and see if a thin grey line (buried surface hoar) is buried one to two feet below the snow surface. If so, look elsewhere to ski and ride.

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.

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 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. 

recent observations

No new human or natural avalanches have seen or reported in the last 24 hours.

Monday, in the Black Lee drainage we found a layer of buried graupel 35 cm from the surface. While our test results showed moderate failure potential and no propagation, this is yet another layer (isolated location possibly) in the snowpack to be on the look out for. Read the snowpack observation here. Also, we continue to find sun crust on any slopes that have a southern aspect, or tilt. While the only current problem with this crust is it's ability to impact your powder skiing and riding, bonding with new snow will be the question of the day? 

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: 18 deg. F.
Average wind direction during the last 24 hours: W-SW
Average wind speed during the last 24 hours: 14 mph
Maximum wind gust in the last 24 hours: 24 mph
New snowfall in the last 24 hours: 3 inches
Total snow depth: inches
weather

The mountains picked up around an inch of new snow overnight. Granite Mountain weather station is reporting 11 degrees with calm winds out of the west-northwest as of 5 am. Today we will have light winds out of the North-northwest becoming calm. Temperatures will be in the 20's and forecasts are calling for only around a half an inch of new snow in the mountains.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Wednesday Wednesday Night Thursday
Weather: Snow likely, mainly after noon. Cloudy, with a high near 26. North northeast wind around 5 mph becoming calm in the afternoon. Chance of precipitation is 60%. Total daytime snow accumulation of less than a half inch possible. Snow. Low around 17. Calm wind. Chance of precipitation is 80%. New snow accumulation of 1 to 2 inches possible. Snow. High near 26. Light and variable wind. Chance of precipitation is 80%. New snow accumulation of 1 to 2 inches possible.
Temperatures: high 26 deg. F. low 17 deg. F. high 26 deg. F.
Wind direction: North-northeast Calm variable
Wind speed: 5 Calm light
Expected snowfall: less than one half in. 1-2 in. 1-2 in.
Granite Mountain at 7700 feet.
  Wednesday Wednesday Night Thursday
Weather: Snow likely, mainly after 11am. Cloudy, with a high near 20. Northwest wind 5 to 8 mph becoming light and variable. Chance of precipitation is 60%. Total daytime snow accumulation of less than a half inch possible. Snow. Low around 15. Southwest wind 5 to 10 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 3 inches possible. Snow. High near 22. Southwest wind 8 to 10 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 3 inches possible.
Temperatures: high 20 deg. F. low 15 deg. F. high 22 deg. F.
Wind direction: Northwest Southwest Southwest
Wind speed: 5-8 5-10 8-10
Expected snowfall: Less than one half in. 1-3 in. 1-3 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.