THIS AVALANCHE ADVISORY EXPIRED ON March 12, 2017 @ 8:00 am
Avalanche Advisory published on March 11, 2017 @ 7:00 am
Issued by Dave Bingaman - Payette Avalanche Center
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The Avalanche Danger is Moderate today above 7000 feet.  Human triggered avalanches are possible on steep, wind loaded terrain.  Below 7000 feet the Avalanche Danger is Low where firm, refrozen snow developed overnight with below freezing temperatures.  As temperatures rise today and if we see periods of direct sun, the potential for loose, wet avalanches will increase.  

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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The rain Wednesday/ Thursday soaked our snowpack to nearly the 8000 ft level.  Decreasing temperatures in the upper elevations have already begun the process of locking up the top 1-2 feet of the snowpack. Wind and storm slabs are still present near the highest ridgelines so you will want to pay attention if you are getting above the elevation that got soaked by the rain.  The widespread rain runnels will be a great visual indicator of where it rained.  A couple of weak layers were showing up yesterday near the bottom of the super saturated snow that are worth mentioning too.  A layer of grauple(ball bearing like snow) around 18 inches(50 cm) down was still failing in compression and another thin layer below that failed in the moderate zone.   Overall the snowpack was stabilizing much quicker than expected given the amount of liquid precipitation that fell on it.  Cooler temperatures in the upper elevations today through Sunday will continue this strengthening process.

Additionally, cornices have already begun trimming themselves back but should still be given a wide berth.  Some of the ridgelines in our area are sporting massive, overhanging cornices right now.

Avalanche Problem 2: Loose Wet
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The snowpack has already begun the process of refreezing and strengthening itself but the surface will be susceptible to loose, wet avalanche activity.  I observed roller ball and point release activity in the surface snow on steep terrain yesterday in the bowls north of Tamarack Resort.  These were mostly confined to the top 3-4 inches of the snowpack.  Last night's cooler temperatures will have done wonders at shutting this down until we see warm temperatures and or direct sun on the firming surface.  If you start punching through the surface snow today or see increasing roller ball activity, you will want to find cooler, firmer slopes.  Temperatures towards the beginning of the week are going to start warming up again and the potential for loose, wet avalanches and or wet slabs will rise again with the temperatures.

advisory discussion

Snowmobiler/Snowbiker Travel Restrictions: 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.  It is your responsiblity to know where closures exist on the forest.

The Granite Mountain Area Closure is in effect Jan15-March 31, please respect Snowcats operating, signed and unsigned closures and other users 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, North of the 20 mile drainage, 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").

Photo 1 is from the edge of the signed Brundage Mt. Ski Area just past the Ski Area parking lot, photo 2 is of sled tracks ignoring Catski terrain signs...there is alot of snow out there folks.  Don't be "that" guy on a sled that gives sledders a bad reputation... please respect closures and other users.

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.We have equipment that is overdue for replacement but lack the funds to purchase new gear including weather station parts and our forecast sleds.  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 started out as a wet, sticky mess in the morning but as a cold front moved through in the afternoon, things quickly began to firm up in the upper elevations.  Evidence of the most recent super soaker event was pretty obvious in the form of widespread rain runnels on the snow surface along the West Mountain crest.  The snowpack was responding to the rain event with some very dense, stable snow in the upper portion of the snowpack.  At 7400 feet yesterday the rain had saturated down about 2 feet into the snowpack and firmed up several of the weak layers that we were seeing prior to the rain event.  At 18-20 inches there was a preserved layer of grauple that failed in my pit tests but was wet enough that it will likely be frozen and well bonded today or tomorrow.  The top 3 or 4 inches of wet snow at the surface was sliding off the more firm layer below in a loose, wet gooey blob on steeper rollovers.  This is likely to be our main problem over the next few days as the snow surface softens during the day.  Given the elevation of the rain, wind slab and storm slab problems are going to be confined to only our highest ridgelines right now.  If you are playing on steep upper elevation slopes pay attention to the snowpack especially if you find colder, unconsolidated snow that escaped the rain on leeward ridgelines.

Rain Runnels in Wildwood Bowl north of Tamarack Resort-7400-7200 ft.

 

Rain Runnels near the top of the West Mountain Ridge near Tamarack Resort-7500 ft.

CURRENT CONDITIONS Today's Weather Observations From the Granite Weather Station at 7700 ft.:
0600 temperature: 27 deg. F.
Max. temperature in the last 24 hours: 33 deg. F.
Average wind direction during the last 24 hours: WSW
Average wind speed during the last 24 hours: 10 mph
Maximum wind gust in the last 24 hours: 27 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: NA inches
weather

 

.SHORT TERM...Pacific frontal system will spread clouds into the
area today. Light rain will begin this afternoon in Baker and
Valley Counties, southern limit Burns, OR, to Cascade, ID. Showers
will shift to the Idaho side this evening especially in the West
Central Idaho Mountains and Boise Mountains, southern limit Vale,
OR, Boise, ID, Fairfield, ID. Clearing west to east Sunday morning.
Continued mild. Light winds through Sunday except moderate west
winds Sunday afternoon in the Magic Valley.

.LONG TERM...Sunday night through Friday...Upper ridge will persist
through Tuesday, leading to well-above normal temperatures.
Temperatures will be the warmest so far this year with valley highs
in the 60s to lower 70s. A system will move through the ridge and
bring a chance of showers to the northern half of the forecast area
(generally north of a Burns-Boise-Fairfield line) Monday afternoon
through Tuesday. A Pacific system and cold front will bring a chance
of showers Wednesday and Thursday, with cooler temperatures
following the front on Thursday. The upper ridge will rebuild on
Friday for slightly warmer temperatures. Pacific moisture will move
through the ridge for a chance of showers, mainly across the north.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Saturday Saturday Night Sunday
Weather: Scattered showers after 11am. Increasing clouds, with a high near 45. South wind 5 to 11 mph. Chance of precipitation is 30% Showers, mainly before 11pm. Low around 31. South wind 6 to 10 mph becoming west after midnight. Chance of precipitation is 80% Mostly cloudy, with a high near 45. South southwest wind 3 to 5 mph.
Temperatures: 45 deg. F. 31 deg. F. 45 deg. F.
Wind direction: S S SW
Wind speed: 5-11 6-10 3-5
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Saturday Saturday Night Sunday
Weather: Scattered snow showers after 11am. Mostly cloudy, with a high near 33. Breezy, with a south southwest wind 10 to 15 mph increasing to 21 to 26 mph in the afternoon. Chance of precipitation is 30%. Total daytime snow accumulation of less than one inch possible. Snow showers, mainly before 11pm. Low around 22. Breezy, with a south southwest wind 13 to 23 mph becoming west northwest after midnight. Chance of precipitation is 80%. New snow accumulation of 1 to 2 inches possible. Mostly cloudy, with a high near 32. West southwest wind 6 to 9 mph.
Temperatures: 33 deg. F. 22 deg. F. 32 deg. F.
Wind direction: SSW SSW then WNW WSW
Wind speed: 10-15 increasing to 21-26 in the pm 11-23 6-9
Expected snowfall: Trace. in. 1-2 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.