THIS AVALANCHE ADVISORY EXPIRED ON March 21, 2019 @ 7:06 am
Avalanche Advisory published on March 20, 2019 @ 7:06 am
Issued by George Halcom - Payette Avalanche Center
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The Avalanche Hazard is Moderate today, The hazard will rise as the Sun and ambient temperature heats up the snow. The heat may produce cornice failures, rollerballs, and wet-loose slides on steep solar influenced slopes, especially near rocks.  Be cautious, and avoid sunny steep slopes that are receiving an excessive amount of heat where you are sinking above your boot tops.  Choose cooler aspects that are not receiving direct Sun.

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
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The snowpack has been getting warm and freezing each night, except Last night, we did not get a good freeze. Every day, we have noticed wet-loose natural avalanches. Some of the bigger natural wet-loose avalanches have already gone off, but others have been popping off, especially near rocks, which is probably the "ground" for some of our favorite upper elevation lines. The heat is warming up not only the snow, but the rocks also, which is where the snowpack is going to be the weakist. 

Stay off steep, really warm, solar effected slopes late in the day. Rollerballs and point releases, as well as an increase in boot, ski and or sled penetration depth in the snow are all indicators that the aspect is picking up too much heat, and you should choose a different, cooler aspect.

 

 

 

 

 

 

 

Avalanche Problem 2: Cornice
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We have seen minimal cornice failure lately, but given the Temperatures, and the size of some of the cornices that are somehow still hanging on over the ridges, It's doubtful that they will survive the temperature swings that we are going to be seeing.  Stay far back from the edges of cornices as they may be stressed out, hanging over, and fail further back than you might expect. 

advisory discussion

PAC will issue 3 Advisories per week through the remainder of the winter as long as funding is available. 

Your Observations are extremely helpful and appreciated by all backcountry users.  If you have not checked our our Observations page, it is really easy to add snow or avalanche info.  Drop down menus and prompts will lead you through it and it is easy to add photos.

Please be aware that there are areas that are CLOSED to motorized traffic in the McCall, Goose Lake and greater West Mountains area.  Just because there are tracks in some areas, does not mean they are open.  Please respect all users and closures.  See the Payette Winter Travel Maps for clarification.  Both the East and West maps can be downloaded on the Avenza app on your phone or are available at trailheads and local shops.   IT IS YOUR RESPONSIBILITY TO KNOW WHERE YOU ARE AND WHERE THESE CLOSURES EXIST. 

recent observations

Yesterday, we traveled to Black Tip, near upper Payette Lake. The groomed trail was very frozen and firm in the morning making us stop a couple of times to cool down our snowmobiles, even with good ice scratchers.  Around 10am, the snow started softening quite a bit,  allowing for cooler travel. Around 11-noon, due South aspects traveled well, and the air temperature felt almost Tropical.

We were still able to find soft, quasi-powder on the Northern aspects, with wind effect on almost all of the upper most Northern aspects where old non-reactive, shallow wind slabs that have a dry, poor bond still exist. Our ski turns on the East aspect of Black Tip around 2PM did not produce wet slides, but almost. The snowmobiling was pretty good as the snow softened, and so was the skiing.

Skiers should be carrying glop stopper, and other waxes to help slide in the warm afternoon snow. Scratchers on snowmobiles are going to be essential on groomed trails (especially early morning) , and if you have a big track you might want to carry spare scratchers in case they break?

 

 

 

 

 

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: 38 deg. F.
Average wind direction during the last 24 hours: NE
Average wind speed during the last 24 hours: 9 mph
Maximum wind gust in the last 24 hours: 20 mph
New snowfall in the last 24 hours: NA inches
Total snow depth: NA inches
weather

 

Area Forecast Discussion
National Weather Service Boise ID
351 AM MDT Wed Mar 20 2019

.SHORT TERM...Today through Saturday...An upper level trough is
undercutting the ridge over the Pacific NW this morning and will
slowly track east across central CA today. Clouds and a chance of
showers increase across southern Harney and Malheur counties and
far southwest Idaho this afternoon with areas to the north
remaining dry and partly cloudy. The trough will move across
southern UT and NV on Thursday, keeping a chance of showers long
the NV border through Thursday afternoon. The trough will begin to
move northward across UT on Friday, keeping a threat of showers
across the area, mainly in the Idaho zones. A cold front will
move onshore on Friday afternoon and move through eastern OR on
Saturday afternoon, and southwest ID on Saturday evening with
showers focused along the cold front and the higher terrain. Snow
levels will start around 6500-7000ft on Friday evening and lower
to 4500-5500ft behind the cold front.

.LONG TERM...Saturday night through Wednesday...Showers will continue
in southwest Idaho Saturday night through Sunday as an upper trough
moves through the region. A weak upper ridge will bring drier
conditions to southeast Oregon by Sunday afternoon. Snow levels will
lower from around 5000 feet Saturday night to 4000 feet on Sunday.
Light snow accumulations are possible in the mountains of central
Idaho. Temperatures will be near normal. The upper ridge on Oregon
will progress eastward and reach Idaho on Monday for dry conditions
across the area. Temperatures will be around 5 degrees above normal.
The next Pacific trough will move inland Tuesday and Wednesday,
bringing a chance of showers by Wednesday. Temperatures will be
around 5 degrees above normal, cooling to near normal on
Wednesday.

&&

.AVIATION...VFR. Mostly clear, except increasing clouds with a
chance of showers near the Nevada border. Snow levels around 6000 ft
MSL. Surface winds: east-southeast 10-20 kts, with gusts to around
30 kts after 18Z. Winds aloft near 10k ft MSL: southeast 20-30
kts.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Wednesday Wednesday Night Thursday
Weather: Sunny, with a high near 52. Light and variable wind. Mostly clear, with a low around 24. Light and variable wind becoming south around 5 mph. Sunny, with a high near 51. Light and variable wind.
Temperatures: 52 deg. F. 24 deg. F. 51 deg. F.
Wind direction: Variable S Light
Wind speed: Light 5 Variable
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Wednesday Wednesday Night Thursday
Weather: Sunny, with a high near 47. South southeast wind around 11 mph. Mostly clear, with a low around 36. East wind around 9 mph. Sunny, with a high near 51. East northeast wind 5 to 8 mph becoming north in the afternoon.
Temperatures: 47 deg. F. 36 deg. F. 51 deg. F.
Wind direction: SSE E ENE-Becoming North
Wind speed: 11 9 5-8
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.