THIS AVALANCHE ADVISORY EXPIRED ON December 29, 2015 @ 6:30 am
Avalanche Advisory published on December 28, 2015 @ 6:30 am
Issued by -
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Below 7,000 feet today the Avalanche Hazard is LOW. Above 7,000 the Avalanche Hazard is MODERATE due to the possibility of triggering a wind slab in steep terrain. These wind slabs are still present near ridge tops and in other terrain features that caught last week's blowing snow. In non-wind loaded terrain, stability is better and avalanches are possible but not likely. Exercise caution in all steep, consequential terrain.

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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We have been talking about wind slabs most of the winter so far.  Wind slabs are still lingering in the upper elevation areas near ridge tops and in a few pockets where the blowing snow can accumulate.  Most of these areas are going to be pretty obvious as a density change or an area of stiffer snow in the otherwise soft snow around them. Look for them below cornices, on steep roll overs, and in natural catcher's mitts like gullies or small depressions on the slope. The wind slabs that we did find yesterday were shallow and only reactive on steep terrain. We were able to get one small wind slab to 'pop' while skinning. But it was sought out on a test slope and only 5 inches deep and on a 42 degree slope. If you were to trigger a similar slab while skiing it could take you for a ride and ruin your day.

Avalanche Problem 2: Loose Dry
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Small loose, dry avalanches or sluffs should be anticipated on large steep, steep confined slopes or on slopes with obstacles below your intended line. These small slides don't pack a lot of punch but can grab you and push you in a direction you don't want to go whether you are on a sled or skis. 

advisory discussion

As time passes our snowpack continues to strengthen. This is great news, however, you should not let your guard down. Travel smart in the backcountry by exposing only one person at a time when on or near avalanche terrain. Wear and know how to use your beacon, probe, and shovel. 

With this weekends cold clear skies, we will expect to see some surface hoar start to develop. If you are out and see any slopes that have surface hoar on them, take a picture and submit an OBSERVATION here on payetteavalanche.org. Or if you see anything else avalanche related....

recent observations

Yesterday we traveled up Lick Creek to see where the wind slabs were still active and if any surface hoar had started to develop. What we found was light powder snow on upper elevation terrain except for a very small sliver of SW aspects where a light crust has developed at the snow surface. This crust is very faint and will hopefully be crushed by our next snow load. Multiple slope cuts were performed on the powder holding aspects with only sluffing in steep terrain. 

weather

A temperature inversion will be in place again today around the advisory area, so do yourself a favor and get up in the mountains. Expect to see temperatures reach into the 20's above 7,000 feet and only stay in the teens in the valley. The skies will be mostly cloudy today with a 30% chance of precipitation. If we do collect any of the soft white stuff it will be less than 1 inch. The next few days will be similar to today, with sunny skies this weekend. A pattern change is expected for Monday of next week that will hopefully bring snow accumulation back into the PAC Advisory Area.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Monday Monday Night Tuesday
Weather: A 30 percent chance of snow showers, mainly before 11am. Cloudy, with a high near 18. Wind chill values between zero and 10. Calm wind becoming west northwest around 5 mph in the afternoon. New snow accumulation of less than a half inch possible. Mostly cloudy, with a low around 3. Light north wind. Mostly cloudy, with a high near 18. Calm wind becoming west southwest around 5 mph in the afternoon.
Temperatures: High 18 deg. F. Low 3 deg. F. High18 deg. F.
Wind direction: North-northwest North West-southwest
Wind speed: 5 Light 5
Expected snowfall: 1 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Monday Monday Night Tuesday
Weather: A 30 percent chance of snow showers. Cloudy, with a high near 23. Wind chill values between zero and 10. West southwest wind 7 to 9 mph becoming north northwest in the afternoon. New snow accumulation of less than one inch possible. A 20 percent chance of snow showers before 11pm. Cloudy, with a low around 8. Wind chill values between -4 and 5. North wind around 8 mph. A 20 percent chance of snow showers. Mostly cloudy, with a high near 21. Wind chill values between -3 and 7. West northwest wind 6 to 8 mph.
Temperatures: High 23 deg. F. Low 8 deg. F. High 21 deg. F.
Wind direction: West-southwest North West-northwest
Wind speed: 7-9 8 6-8
Expected snowfall: 1 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.