THIS AVALANCHE ADVISORY EXPIRED ON January 29, 2017 @ 7:07 am
Avalanche Advisory published on January 28, 2017 @ 7:07 am
Issued by Dave Bingaman - Payette Avalanche Center
bottom line

The Avalanche Danger is Moderate, human triggered avalanches are possible in isolated areas today.  Persistent weak layers, ice crusts or crust /facet combinations can be found buried in some areas. Wind slabs of varying thickness exist near ridgelines and on exposed upper elevation terrain.  Pay attention to changing snow conditions as temperatures climb throughout the day. Use good travel techniques, ski or ride one at time and keep your eyes on your partners in steep terrain today.

How to read the advisory


  • Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Normal Caution
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  • Likelihood ?
    Certain
    Very Likely
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  • Size ?
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With warming temperatures, minimal wind and no new precipitation, Avalanche Conditions are improving throughout the area.  No new slides have been reported or observed.  No reports of cracking, collapsing or otherwise unstable snow have been observed over the last few days...However,  we are still tracking several weak layers that were scattered throughout the snowpack before last week's warm and windy storm.  

While the likelihood of triggering these layers is decreasing, you should still be aware that in protected, lower elevation areas there is still a layer of Buried Surface Hoar.  Instabilities also exist at the interface between the recent storm snow and the old snow surface in wind protected, treed areas in the middle elevations where fine grained faceted snow was present.  We have also seen thin areas in the snowpack near ridgetops over the last week that are harboring a shallow crust with very weak faceted snow below.   The possibility of triggering a wind slab will remain a concern if you are in steep, wind exposed terrain. In addition, inversion conditions mean daytime warming will play a role in snow conditions today,  expect to see an increase in shallow, loose avalanches on sun affected terrain as temperatures climb.  

Normal caution means safe and smart travel techniques: one at a time on steep slopes, keeping your eyes on your partners, being aware of changes in the snow pack as you travel and using extra caution on steeper terrain.  While Avalanche Conditions are improving, there are still areas that you should be suspicious of.

advisory discussion

Remember your information can SAVE LIVES!! If you see anything we should know about, please participate in the creation of our own community avalanche advisory by submitting snow and avalanche conditions. It's okay if you leave some fields blank, just fill out what you know and/or submit photos. You can  also email us at  forecast@payetteavalanche.org.

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

Yesterday, temperatures climbed into the 30's, the sun was out in force and the snowpack noticed.  Today, you can expect to find crusts forming on the Southerly aspects as well as an increase in shallow, loose avalanches occurring as the combination of daytime warming and direct sun break down the bonds in the loose surface snow.  Expect to see activity follow the sun with steep, rocky slopes on the East side of the compass starting things off.  As the day progresses loose activity will swing around to the South and Southwest.   Soft snow conditions exist on aspects protected from the sun.

Yesterday in the 20 Mile drainage, George got these photos of loose activity on an ESE face and of the wind effect near the ridgelines. He did not find any sheltered areas that were harboring instabilities from the buried layers that existed prior to last week's storm.

 

                                                      

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: 31 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 4 mph
Maximum wind gust in the last 24 hours: 15 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 76.3 inches
weather

 

SHORT TERM...Current atmospheric trends along with model data indicate that the ridge of high pressure will remain in control this weekend. Persistence will be the rule forecast-wise across the area. The valley inversions will remain in place, and higher elevations above the inversion will slowly warm both today and Sunday. Abundant sunshine will grace higher elevations, while most lower valley areas will see mainly clouds with occasional breaks. Temperatures will remain well below average for locations beneath the inversion. While the chance for precipitation is very low, some areas under the stratus will experience brief periods of light snow off and on through the weekend. 

LONG TERM...Sunday night through Friday...Upper ridge and underlying inversion hold through Tuesday and possibly into Wednesday. A trough approaching the CA coast will initiate precipitation along a frontal boundary, which models continue to position along the OR/WA border into central Idaho Tuesday night. Precipitation spreads south Wednesday into Thursday as the upper trough moves inland. Lower elevations will see a mix of precipitation with snow changing to rain or freezing rain during the day Thursday as the inversion erodes. In the mountains the snow levels will rise to 4-5k feet MSL by Thursday afternoon. The trough lifts across the interior northwest on Friday keeping a chance of rain and snow showers.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Saturday Saturday Night Sunday
Weather: Patchy fog after 11am. Areas of freezing fog before 11am. Otherwise, mostly sunny, Patchy fog before 11pm. Patchy freezing fog after 11pm. Otherwise, mostly cloudy, Patchy freezing fog before 11am. Mostly sunny
Temperatures: 28 deg. F. 6 deg. F. 30 deg. F.
Wind direction: Calm Calm Calm
Wind speed: 0 0 0
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Saturday Saturday Night Sunday
Weather: Mostly Sunny. Mostly Cloudy. Mostly Sunny.
Temperatures: 30 deg. F. 17 deg. F. 31 deg. F.
Wind direction: Variable SW SW
Wind speed: Light Around 5 after midnight 6-11
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.