THIS AVALANCHE ADVISORY EXPIRED ON January 24, 2017 @ 6:26 am
Avalanche Advisory published on January 23, 2017 @ 6:26 am
Issued by Kent May - Payette Avalanche Center
bottom line

The avalanche danger is CONSIDERABLE today above 6000 feet on slopes over 30 degrees due to human triggered avalanches being likely. Below 6000 the avalanche danger is MODERATE and human triggered 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: Persistent Slab
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They don't call it persistent for nothing.

A relatively widespread layer of surface hoar and near surface facets is now laying below one to two feet of snow. This layer developed over the high pressure (clear skies) previous to last weeks dump. While out, continue to dig down and look for this 'grey' looking line in the snowpack. We are finding it on east, northeast, north, northwest, and west aspects in middle elevations and in higher areas that were protected from the winds that accompanied last weeks storm. Where are you finding it, or better yet, not finding it? We want to know!

Surface Hoar and faceted snow layers are responsible for more avalanche accidents and fatalities than all other types of avalanches combined.

While I am gaining a little bit of confidence in it's strength (failure of weak layer is harder to initiate in compression test), I am still very weary of the weak layers energy and ability to propagate (see Dave's video of propagation saw test) Until we can gain some confidence in this layer (no new natural or human triggered avalanches), you should continue to keep this problem as your top concern and talk about it with your backcountry partners. 

The picture below shows a close up of the surface hoar layer at the height of the saw.  Contest: First person to send a picture/observation of surface hoar in our current snowpack gets a free FRIENDS OF PAYETTE AVALANCHE CENTER t-shirt!

        

Avalanche Problem 2: Wind Slab
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With variable winds, and new light density snow available for transport, yet another new layer of fresh (touchy/easy to trigger) wind slabs can be found today. With the variable winds, be on the lookout for these fresh slabs on most all aspects in the upper elevations. 

Lurking below the new wind affected snow, still lingers older stiffer (harder to trigger) wind slabs. Be conscious of  the ability of these older slabs to 'step down' into older layers of snow, and even cause a failure of our buried persistent weak layers. If this scenario played out it could cause for a large, possibly fatal avalanche. 

Evaluate terrain choices carefully today. Use safe travel protocols...Or better yet, stay away from slopes over 30 degrees and enjoy the fresh powder on low angle slopes and in the meadows.

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 snd Sargeant's 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 were reported over the weekend. If you did see or trigger an avalanche, we would like to know.

CURRENT CONDITIONS Today's Weather Observations From the Granite Weather Station at 7700 ft.:
0600 temperature: 13 deg. F.
Max. temperature in the last 24 hours: 19 deg. F.
Average wind direction during the last 24 hours: SE
Average wind speed during the last 24 hours: 7 mph
Maximum wind gust in the last 24 hours: 29 mph
New snowfall in the last 24 hours: 4 inches
Total snow depth: inches
weather

4 to 6 inches of light density snow fell yesterday afternoon. Over the last 24 hours on Granite Mountain winds were primarily out of the southeast, but are currently out of the east and northeast as of 5 am. Gust over the last 24 hours maxed out as high as 29 mph with temps in the teens. Today we should see cloudy skies and less than an inch of new snow...if any, and temps climbing into the low 20's. Slight chance of snow all week, with high pressure building over the weekend.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Monday Monday Night Tuesday
Weather: A 20 percent chance of snow. Mostly cloudy, with a high near 30. Northeast wind around 5 mph becoming light and variable. A 30 percent chance of snow, mainly before 11pm. Mostly cloudy, with a low around 12. North wind around 7 mph. Little or no snow accumulation expected. A 20 percent chance of snow. Mostly cloudy, with a high near 25. North northeast wind around 5 mph becoming light and variable in the morning.
Temperatures: high 30 deg. F. low 12 deg. F. high 25 deg. F.
Wind direction: northeast north north-northeast
Wind speed: 5 becoming light 7 5 becoming light
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Monday Monday Night Tuesday
Weather: A 30 percent chance of snow, mainly after 11am. Mostly cloudy, with a high near 23. Wind chill values between -2 and 8. North northeast wind 7 to 16 mph. Total daytime snow accumulation of less than a half inch possible. A 30 percent chance of snow, mainly before 11pm. Mostly cloudy, with a low around 14. North northeast wind 14 to 17 mph. New snow accumulation of less than a half inch possible. A 20 percent chance of snow. Mostly cloudy, with a high near 20. Wind chill values between -1 and 9. North wind 9 to 14 mph.
Temperatures: high 23 deg. F. low 14 deg. F. high 20 deg. F.
Wind direction: north-northeast north-northeast north
Wind speed: 7-16 14-17 9-14
Expected snowfall: Less than .5 in. Less than 0.5 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.