THIS AVALANCHE ADVISORY EXPIRED ON December 26, 2015 @ 11:27 pm
Avalanche Advisory published on December 25, 2015 @ 11:27 pm
Issued by Dave Bingaman - Payette Avalanche Center
bottom line

The Avalanche Hazard is Moderate today. Pockets of Considerable Hazard still exist on Northerly ridge tops where S and SW winds have created fresh wind slabs in the new snow. Wind slabs may also be encountered on E or W facing slopes especially in gullies or other terrain features that catch the blowing snow. Overall, the new snow is doing a good job bonding to the older snow layers below creating a deep, dry, user friendly snowpack throughout the area.

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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Be aware that you could still trigger a shallow or deep wind slab on upper elevation wind loaded slopes. New slabs were forming on Thursday as the winds picked up and the new snow came in at a slightly warmer temperature than the cooler snow on the ground.  Temps dropped quite a bit Thursday night and dried out the snow but remember that cold temperatures do a great job preserving wind slabs and other weaknesses in the snowpack. You will be able to spot wind affected slopes literally from a mile away, look for and avoid sculpted or pillowed features as you make your terrain choices.

Avalanche Problem 2: Loose Dry
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The light, dry snow is moving easily on steeper slopes and it could push you off course on a sled or skis.  Be aware of sluff potential and your exit options if you are riding or sliding in steep, confined terrain or terrain with obstacles or cliffs below you. 

recent observations

With COLD temps over the last two days the new snow has continued to dry out leaving behind some literally blower powder as a great Christmas present.  If you are getting out in the backcountry right now, you know exactly what we are talking about.  While we have been seeing a few weak layers in the new snow, these layers lack the ability to propagate or spread across even our small test blocks when initiated.  Watch for surface hoar growth over the next few days, clear nights and light winds are exactly what will build our next weak layer.  Let us know if you are seeing pockets of surface hoar while you are out traveling.

CURRENT CONDITIONS Today's Weather Observations From the Granite Weather Station at 7700 ft.:
0600 temperature: no data deg. F.
Max. temperature in the last 24 hours: deg. F.
Average wind direction during the last 24 hours:
Average wind speed during the last 24 hours: mph
Maximum wind gust in the last 24 hours: mph
New snowfall in the last 24 hours: inches
Total snow depth: inches
Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Friday Friday Night Saturday
Weather: Areas of fog. Otherwise, mostly sunny. Wind chill values between -7 and 3 Patchy fog. Otherwise, mostly cloudy, with a temperature rising to around 8 by 5am. Wind chill values between -3 and -8. Patchy fog before 11am. Otherwise, mostly cloudy
Temperatures: 17 deg. F. 1 deg. F. 22 deg. F.
Wind direction: South South southeast becoming calm. Calm wind becoming south southwest around 5 mph in the afternoon.
Wind speed: 5 5 Calm
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Friday Friday Night Saturday
Weather: Mostly sunny, with a high near 16. Wind chill values between -7 and 3. Mostly cloudy, with a temperature rising to around 15 by 5am. Wind chill values between -5 and zero. Mostly cloudy, with a high near 22. Wind chill values between -1 and 8.
Temperatures: 16 deg. F. 9 deg. F. 22 deg. F.
Wind direction: North northwest South southwest South southwest wind
Wind speed: 5-7 9-17 16-18
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.