THIS AVALANCHE ADVISORY EXPIRED ON February 17, 2017 @ 7:13 am
Avalanche Advisory published on February 16, 2017 @ 7:13 am
Issued by George Halcom - Payette Avalanche Center
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The avalanche danger is CONSIDERABLE today at all elevations where natural avalanches are possible, and human triggered avalanches are likely. Loose wet natural avalanches are possible below 6500 feet where rain is falling on the snow surface. Above 6500 feet, new snow may have trouble bonding to slick snow surfaces created from the sun this past week. Elevations above 7,000 feet will see South winds upwards of 38MPH creating fresh wind slab avalanche hazard.

 

 

How to read the advisory


  • Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Loose Wet
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Rain on snow below 6500 feet is going to give us the possibility of wet loose avalanches. At 5 am this morning it was 35 degrees at the Brundage Resevoir Snotel, and the Brundage base area webcam was soaked. Human triggered, wet-loose avalancches are likely in steep rain saturated terrain. 

 

 

Avalanche Problem 2: Storm Slab
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The new snow is coming in warm and wet, which should be a good recipe to bond to the old snow surface...this might be tough in some areas that had slick sun crusts (SE. S. SW, WSW), and that is where the new storm snow may have trouble staying put, especially on slope angles above 30 degrees. We may possibly see natural avalanches, and its likely that skiers and sledders could trigger avalanches on theese areas that have snow resting on a slick sun crust. 

Avalanche Problem 3: Wind Slab
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Winds out of the South-Southwest around 20-30 MPH have been pushing snow since yesterday afternoon. Expect fresh wind slab hazard on all aspects, as mountains influence how the wind loading takes place. Some of theese slabs will have trouble holding on to the slick Sun crusts, and may fail naturally...terrain over 30 degrees should be aproached carefully as the wind slabs may just be waiting for a trigger like you? Human triggered avalanches are likely on the fresh wind slabs today.

advisory discussion

Snowmobiler/Snowbiker Travel Restrictions: Granite Mountain Area Closure is in effect Jan15-March 15, please respect Snowcats operating in this and nearby areas.  In addition there are other areas on the Payette National Forest that are CLOSED to snowmobile traffic including Jughandle Mt east of Jug Meadows,North of Boulder Mtn, East of Rapid Peak,  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.

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.

recent observations

Yesterday, we toured out to  Boulder Lake. The snow surface was firm from all of the the melt and freeze over this past week. Aspects that had a tilt towards the Sun formed a stout, slick , almost mirror like crust on the snow surface making for some sub-par, almost challenging, skinning, skiing, and sledding conditions. Clouds came in along with wind, and kept the snow surface above Boulder Lake from ever softening up. Shaded aspects at upper elevations had 2-4 inches of soft snow that was a mixture of wind slab and recrystalized powder. We noticed some overhanging cornices that are continuing to grow near the ridge lines, as seen in this photo below of the North side of Jughandle Mtn.

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CURRENT CONDITIONS Today's Weather Observations From the Granite Weather Station at 7700 ft.:
0600 temperature: 29 deg. F.
Max. temperature in the last 24 hours: 30 deg. F.
Average wind direction during the last 24 hours: Southwest
Average wind speed during the last 24 hours: 12 mph
Maximum wind gust in the last 24 hours: 35 mph
New snowfall in the last 24 hours: 3 inches
Total snow depth: NA inches
weather

Today, around 7600 ft, expect Snow. Temperature falling to around 26 by 3pm. Breezy, with a south wind 20 to 28 mph, with gusts as high as 38 mph. Chance of precipitation is 100%. New snow accumulation of 5 to 9 inches possible.Snow levels will range from 5500-6500 feet.

A weak cold front will swing through the area late this afternoon through early this evening. Instability exists along the front - not enough to warrant thunderstorms, but there could be heavier showers accompanied by graupel. A short wave ridge will move in late tonight and remain across much of the area through Friday. The next Pacific system will remain generally to our south but moisture could work northward ahead of it for a slight chance of showers along the Nevada border Friday afternoon. .

LONG TERM...Friday night through Wednesday...Dynamic pattern shaping up for the extended period. General moist southwest flow will set up through Wednesday, bringing abundant moisture and keeping southwest Idaho and southeast Oregon on the cusp of a large temperature gradient, with warmer than normal temperatures towards Twin Falls and cooler than normal temperatures toward Baker City. Upper level troughing off the Pacific Northwest coast will push a series of waves through the region. An upper level trough breaks off the parent flow and moves into southern CA. A warm front associated with this system moves into the region on Saturday morning with widespread precipitation through Saturday afternoon, snow levels range from 5,500 to 6,500ft. As the southern CA trough moves east, a weak shortwave and cold front moves through on Sunday morning. Then, a strong warm front and atmospheric river takes aim at northern CA on Monday morning. Snow levels rise to around 8,000ft on Monday afternoon for a short time as the warm sector moves over the area, with heavy precipitation over the central Idaho mountains. With strong southwest flow aloft, temperatures in the southern Snake Plain have the potential to approach 60F if the area becomes rain shadowed from the Owyhees, but will hold off for now on forecasting this. Finally the cold front with this system moves through sometime Tuesday lowering snow levels to around 3,000ft. After Wednesday, things begin to get interesting as a blocking ridge develops in the Gulf of Alaska, allowing colder air to move south along the West Coast into our region. Snow levels fall to the valley floors on Thursday with snow showers and below normal temperatures thereafter.

 

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Thursday Thursday Night Friday
Weather: Rain before 11am, then rain and snow. High near 40. South wind around 10 mph. Chance of precipitation is 100%. Little or no snow accumulation expected. Rain and snow showers, mainly before 11pm. Low around 28. South wind 6 to 8 mph. Chance of precipitation is 90%. New snow accumulation of less than a half inch possible. A 30 percent chance of snow showers before 11am. Mostly cloudy, with a high near 39. South southeast wind around 5 mph becoming light and variable in the morning. New snow accumulation of less than a half inch possible.
Temperatures: high 40 deg. F. low 28 deg. F. high 39 deg. F.
Wind direction: South South South-southeast
Wind speed: 10 6-8 5
Expected snowfall: 0 in. less than one half in. less than one half in.
Granite Mountain at 7700 feet.
  Thursday Thursday Night Friday
Weather: Snow. Temperature falling to around 26 by 3pm. Breezy, with a south wind 20 to 28 mph, with gusts as high as 38 mph. Chance of precipitation is 100%. New snow accumulation of 5 to 9 inches possible. Snow showers. Low around 22. South southwest wind 9 to 17 mph. Chance of precipitation is 90%. New snow accumulation of 1 to 3 inches possible. A 30 percent chance of snow showers before 11am. Cloudy, with a high near 32. Southeast wind around 9 mph. New snow accumulation of less than a half inch possible.
Temperatures: high 26 deg. F. low 22 deg. F. high 32 deg. F.
Wind direction: South South -southwest South-southeast
Wind speed: 20-28 Gusting to 38MPH 9-17 9
Expected snowfall: 5-9 in. 1-3 in. less than one half 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.