Avalanche Advisory published on March 22, 2017 @ 6:45 am
Issued by George Halcom - Payette Avalanche Center
bottom line

The Avalanche Danger is Moderate today at all elevations and aspects.  Human triggered loose, wet avalanches remain possible on all steep slopes.  On leeward facing slopes in the highest elevations, you may encounter thin wind slabs that are reactive to the weight of a skier or snowmobile.   Cornice failures are also a major concern,  large cornices are overhanging ridge lines much farther than you might expect.  Avoid traveling near the edges of and spending time below heavily corniced ridgelines.

How to read the advisory

  • Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Loose Wet
  • Character ?
  • Aspect/Elevation ?
  • Likelihood ?
    Very Likely
  • Size ?
    Very Large

Last night, freezing temperatures returned to the mountains after quite a bit of rain on snow above 8,000 feet, and a sustained lack of freezing temperatures that lasted for around 24 hours. The freeze won't last long below 7,000 feet today where temperatures are forecasted to climb back up above freezing, and if the Sun pokes it's head out we will possibly see some loose-wet, shallow natural avalanches, especially on Southern aspects. 

Cornices are a serious concern right now as well, if you are up high near ridge lines, yo can see monster cornices on pretty much all of the leeward slopes.  Avoid travel on or near corniced ridge lines and limit the amount of time you spend on slopes below them as well.



Avalanche Problem 2: Wind Slab
  • Character ?
  • Aspect/Elevation ?
  • Likelihood ?
    Very Likely
  • Size ?
    Very Large

With an inch or two of new snow last night and gusts from the Southern end of the compass, you may find some shallow 2-4 inch fresh wind slabs that could be sensitive to the weight of person. Today, the forecasted 15MPH winds in the upper elevations will continue to grow shallow wind slabs.




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 responsibility 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").  

Ski areas are closed to snowmobile traffic, last week a group of snowmobilers poached the Northern portion of Tamarack Resort crossing under a fixed and signed rope line and left trenches on 3 of the ski runs that don't get groomed. Don't be "that guy" that gives sledders a bad name, please respect boundaries, snowmobiling at a ski resort is a low blow and a safety concern.

recent observations

No new avalanches were reported or observed, skiing and snowmobiling the last few days has been a mushy, slushy, sometimes enjoyable, mostly sticky mess.  Warm temps have turned the upper snowpack into something that resembles a melting snowcone.

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: 36 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 7 mph
Maximum wind gust in the last 24 hours: 33 mph
New snowfall in the last 24 hours: NA inches
Total snow depth: NA inches

SHORT TERM...As of 2 AM MDT clouds continue to stream nne
through our area but little if any pcpn is falling. Upper
trough off the NW coast is shifting east but will split as it
comes inland, with the main parts going north and south of us
this afternoon and tonight. As a result, showers will develop
again today in our northern and southern mountain areas, as
well as in Harney County. Other areas, including the Treasure
and Magic valleys, will have only a slight chance of showers.
Instability will be weaker than yesterday but still enough for
a slight chance of thunderstorms this afternoon and evening,
except in and near the Boise Mountains and Camas Prairie.
After a relatively cool night under the split upper trough,
Thursday will be dry and a little cooler than today as the next
short wave ridge builds in from the west. Warming with the
ridge will come Friday. Winds will be light west or northwest
today, light and variable tonight, then light to moderate
northwest Thursday. Gusts to 25 mph are expected Thursday
afternoon in the Upper Treasure and western Magic valleys.

.LONG TERM...Thursday night through Wednesday...An active pattern
will bring a series of upper troughs across the Pac NW through the
period. The first system tracks across the region Fri/Sat with
moderate precip amounts and snow levels of 5-6k feet. Saturday night
and Sunday are dry for most areas, though southeast Oregon will see
precipitation chances increase Sunday afternoon as the next upper
wave approaches the coast. While there are differences in the
pattern evolution between the ECMWF and GFS early next week, both
solutions keep the area wet and cool Sunday night through Tuesday.
Snow levels will hold around 5k feet. Drier conditions on Wednesday
as a short wave ridge passes. Temperatures are within a few degrees
of normal through the period.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Wednesday Wednesday Night Thursday
Weather: Scattered showers, with thunderstorms also possible after noon. Mostly cloudy, with a high near 45. South wind 8 to 10 mph. Chance of precipitation is 40%. A chance of rain showers before midnight, then a chance of rain and snow showers. Some thunder is also possible. Mostly cloudy, with a low around 28. Light and variable wind becoming north 5 to 7 mph after midnight. Chance of precipitation is 40%. Little or no snow accumulation expected. Mostly sunny, with a high near 43. North northeast wind around 5 mph becoming light and variable in the afternoon.
Temperatures: 45 deg. F. 28 deg. F. 43 deg. F.
Wind direction: S N NNE-variable
Wind speed: 8-10 5-7 5 becoming light
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Wednesday Wednesday Night Thursday
Weather: Scattered snow showers. Some thunder is also possible. Mostly cloudy, with a high near 33. South southwest wind 11 to 16 mph. Chance of precipitation is 40%. New snow accumulation of less than one inch possible. A 50 percent chance of snow showers. Some thunder is also possible. Mostly cloudy, with a low around 21. South southwest wind 7 to 10 mph becoming north after midnight. New snow accumulation of 1 to 2 inches possible. Partly sunny, with a high near 31. North wind 5 to 7 mph becoming calm in the afternoon.
Temperatures: 33 deg. F. 21 deg. F. 31 deg. F.
Wind direction: SSW S becoming N N
Wind speed: 11-16 7-10 5-7 becoming calm
Expected snowfall: less than one in. 1-2 in. 0 in.

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.