THIS AVALANCHE ADVISORY EXPIRED ON February 20, 2020 @ 7:36 am
Avalanche Advisory published on February 19, 2020 @ 7:36 am
Issued by George Halcom - Payette Avalanche Center
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The Avalanche Hazard today is Moderate above 7000 feet on wind loaded slopes steeper than 30 degrees. Below 7,000 feet the Avalanche Hazard is Low. Human triggered avalanches are possible on upper elevation, wind loaded terrain.

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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    Certain
    Very Likely
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  • Size ?
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Its been a few days since it has snowed so the wind slab instabilities should have mostly healed, or ran naturally by now. Yesterday, near Secesh Summit, North of McCall, we observed some decent wind sculpting on an 8,000 foot East face. Given the structure of the snow pack its possible to kick loose a small wind slab in terrain that has been loaded or cross-loaded by the wind.

The wind has swirled around from Northern and Southern directions, so pay attention to clues like sculpting, drifts, pillows, and Cornices. If you have red flags going off like cracking, hollow sounds, or woomphing, turn around and choose another area to play in.

Some of the large, gigantic Cornices in our mountains may be sensitive, and they may very well fail much further back than you think. Be cautious on the ridges, and give the edges room and the respect they deserve.

Avalanche Problem 2: Persistent Slab
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    Certain
    Very Likely
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We have been finding some random small fragments of buried surface hoar In out test pits about a foot deep throughout the advisory area this week, we have seen this layer producing moderate, broken failures in compression, and lacking the ability to propagate in extended column tests.  The foot or so of new, dry. light density snow above it has produced natural, small avalanches that have mostly been loose avalanches that did not propagate.

Evaluate slopes carefully that are steep and protected, and definitely spread out in steep terrain, use good safe travel protocols

advisory discussion

The Friends of the Payette Avalanche Center's Annual Fundraiser is this coming Friday, Februrary 21st at Banyons clubhouse on the McCall golf course. This year we will have a Silent Auction and Choose your own raffle prizes!  Live music by Jughandle Parade from 6-9!  Our goal this year is to raise $5000. which will go directly into additional forecasts for next season, our future forecasters scholarships and providing more Avalanche Awareness classes.  Tickets will be sold at the door.  $10.00 gets you in the doors with a raffle ticket.  Come on out and help make this years fundraiser this biggest yet!!

 

*Skiers and Snowmobiliers, the Granite Mountain closure went is in effect from January 15-March 31. Please respect Brundage Catski terrain closures which are CLEARLY marked on the west side of Goose Lake.  There is a shared use route at the northern end of the closure to allow access to Granite Mt Lookout and the upper east face of Granite Mt.  Additionally, public motorized use of ANY other Catski road is not permitted, including the roads between Brundage Reservoir and the East side of the Goose Lake Road in the Slab Butte and 76 areas. Please respect closed roads and areas and only ride on open roads and in open terrain.  There are also other areas that are closed to snowmobiling in the West Central Mountains. Click here for the Payette National Forest Winter Travel Map.

*Note to skiers accessing Jughandle Mountain from Silver Fox Trail.  Please park in signed areas only. Blocking or narrowing the road could result in loss of access to this area, ticketing or towing by Valley County.  There is NO parking allowed on the East side of the road or in the snowplow turnaround.  If you can't park in the signed area, park further down the road in a place where you are not obstructing traffi

recent observations

 

Yesterday, near Deep Lake we observed instabilities mostly in the new upper foot of light dry snow. We observed mostly small loose dry point releases, except a couple of small R2, D1-D2 wind slabs on upper exposed West aspects. Our stability tests revealed a buried surface hoar layer 32 CM/ 12 inches down that failed to propagate a fracture in extended column tests. We skied some steep North aspects and only had good things to say about them. We spoke with some riders from the Sawtooths that had not seen anything in the last couple days and submitted an observation on our website.

PAC Volunteer Andy Keck looking at the surface hoar crystals buried beneath the new snow.

Getting no propagation on an extended column test.

bootom layers were 1finger plus hardness.

 PAC Volunteer Annie Halverson testing the new snow on a North Aspect adjacent to our pit.

 

 

 

***If you are out in the mountains and see recent avalanches, please take advantage of the good visibility and snap a picture to submit on our Observations page.

CURRENT CONDITIONS Today's Weather Observations From the Granite Weather Station at 7700 ft.:
0600 temperature: 8 deg. F.
Max. temperature in the last 24 hours: 24 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 5 mph
Maximum wind gust in the last 24 hours: 12 mph
New snowfall in the last 24 hours: NA inches
Total snow depth: NA inches
weather

 

Area Forecast Discussion
National Weather Service Boise ID
313 AM MST Wed Feb 19 2020

.SHORT TERM...Today through Saturday...Continued mostly clear
and very dry through Friday with cold nights and slowly warming
days Thursday and Friday. Forecast is based on persistence with
slight adjustments due to the models. Upper ridge will pass
overhead tonight and Thursday but will have little effect on
surface conditions except a little more warming at higher
elevations. On Saturday the ridge will be east of us and
southwest flow aloft will bring clouds to southern areas and
a few weather changes. Forecast for Saturday is based more
on the models which show a milder night and higher dew points,
and finally above normal high temps. Winds through Friday
will be east or southeast, strongest Thursday afternoon with
speeds 20 to 30 mph in the central Snake Basin.

.LONG TERM...Saturday night through Tuesday...A system will move
into the region sometime on Sunday. Depending on the timing of
the system, snow levels may start near the valley floors before
rising to 3500-4500ft ahead of the cold front. Temperatures will
be near normal on Sunday before falling to around 5 degrees below
normal on Monday and Tuesday. Conditions will generally dry out
Monday and Tuesday except for lingering snow showers over the
mountains.

&&

.AVIATION...VFR. Surface winds: generally E-SE 5-10KT. Winds
aloft near 10kft MSL: NE 5-15KT shifting to SW 10-20KT by 12z/Thu.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.

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 24. Calm wind. Clear, with a low around -2. Calm wind. Sunny, with a high near 27. Light and variable wind.
Temperatures: 24 deg. F. -2 deg. F. 27 deg. F.
Wind direction: Calm Calm Variable
Wind speed: 0 0 Light
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Wednesday Wednesday Night Thursday
Weather: Sunny, with a high near 27. Wind chill values between -1 and 9. East wind around 5 mph becoming light and variable in the afternoon. Clear, with a low around 9. Light south wind becoming southeast 5 to 9 mph in the evening. Sunny, with a high near 32. South wind 9 to 13 mph.
Temperatures: 27 deg. F. 9 deg. F. 32 deg. F.
Wind direction: E S S
Wind speed: 5 5-9 9-13
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.