Avalanche Advisory published on March 27, 2020 @ 12:03:
This advisory is valid for 24 hours
Issued by Dave Bingaman -
bottom line

How to read the advisory

The Avalanche Hazard is Moderate today.  Natural avalanches are unlikely, but human triggerd avalanches are possible. You may be able to trigger isolated wind slabs in upper elevation terrain.  THIS WILL BE OUR FINAL ADVISORY OF THE SEASON.  DUE TO STAY AT HOME ORDERS FOR THE STATE OF IDAHO, PAC IS SHUTTING DOWN A WEEK EARLY.  


Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern. Natural avalanches unlikely; human-triggered avalanches possible. Small avalanches in specific areas; or large avalanches in isolated areas.
weather

 

.DISCUSSION...Generally quiet conditions this morning. A push of
moisture this afternoon could generate a few showers over the
West Central and Boise Mountains, with dry conditions continuing
otherwise. A stronger push of moisture expected Saturday, with
activity continuing and increasing in coverage through Sunday.
Forecast remains on track, no changes to immediate forecast
planned.

 

recent observations

Just North of of McCall on Tuesday, near Fisher Creek saddle, our test pit on a North aspect at 7671ft showed 25cm/ 10 inches of soft dry new snow on top of a thin crust with good bonding. Total snow height was 235cm/ just a little over 7 and a half feet. Some 2-3mm graupel was mixed in the new snow. Compression tests came out hard, CT28, and broken. The crust was not noticeable on the North aspect that we skied From 8,400ft all the way down to 6,700ft. During our climb up the East face of South Bruin, we saw evidence of Southern wind transport and scouring on exposed E and SE ridges, as well as a variety of crust combinations that broke in places just under our skis. Solar crusts on E,SE, and South were noticeable and difficult to skin at times, especially where scoured by the wind.  Visibility was limited at times with cold, moderate ESE winds, and snowy conditions.

 

Avalanche Problem #1: Wind Slab

Older wind slabs formed under some pretty strong winds. Yesterday afternoon we had good conditions for new wind slab development  with moderate winds and light density snow. Expect wind slabs, 3-20 inches thick, in the upper elevations, that may have formed on a crust, and in some places the wind will have scoured all the new snow off of firm Sun and temperature crusts.

If you notice any red flags like cracking or whoomphing, be cautious and turn around or find another slope or route.  Pay attention to any signs of pillows or scouring, and maintain good travel protocols, and extra cation on slopes that are wind loaded, above 7,000 feet, and steeper than 30 degrees. Wind slabs tend to form a bit below ridgelines and cornices enough to suck you into the point of no return.

 

 

advisory discussion

This will be the last PAC update of the season.  Thank you to the Friends of the Payette Avalanche Center, all of our sponsors, everyone that submitted observations and all of our AWESOME Volunteer Travel Companions that help us gather the info we use to create our advisories.  Also, if you are out in the mountains close to your home, you can still submit observation through our observations page.  Stay healthy!

 Snowmobile Parking Lots that are closed as of 3/27/2020: Wallace Lane in the New Meadows Valley, West Face, and Gordon Titus upper elevation near Brundage.  All Boise National Forest Campgrounds, Hot Springs, Snowmobile Parking Lots

IDL LOTS:  Francis Wallace, Green Gate, and Brush Creeck are still open but not being plowed or maintained.

As per the Governor of Idahos orders, non essential travel and recreation outside your local area have been paused for 21 days and are citable offenses under Valley and Adams County Laws. Vehicles in closed areas or open areas with out of area license plates may be fined or towed.  The Governor's orders did not prohibit recreation or excercise close to your home or on IDL and USFS managed lands.  The trailheads that have been closed were closed to limit the number of out of area visitors coming to our area to recreate.

https://valley-county-covid-19-response-valleycounty.hub.arcgis.com/

https://www.facebook.com/payettenationalforest/photos/pb.667908866639038.-2207520000../2795241153905788/?type=3&theater

file:///C:/Users/gyoung/AppData/Local/Microsoft/Windows/INetCache/IE/G9FC3H6C/fseprd716475.pdf

Also,  No uphill travel or parking is allowed at Brundage Mountain Resort, and please don’t ride your Snowmobile at Brundage Mountain Resort, or within the BMR permit area which includes areas adjacent to the resort. It is illegal even though the resort is closed.  

CURRENT CONDITIONS  Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 21 deg. F.
Max. temperature in the last 24 hours: 28 deg. F.
Average wind direction during the last 24 hours: S
Average wind speed during the last 24 hours: 4 mph
Maximum wind gust in the last 24 hours: 13 mph
New snowfall in the last 24 hours: inches
Total snow depth: NA inches
Two-Day Mountain Weather Forecast  Produced in partnership with the Reno NWS
For 7000-8000 ft.
  Friday Friday Night Saturday
Weather: Isolated snow showers after noon. Partly sunny, with a high near 37. Calm wind becoming west southwest around 5 mph in the afternoon. Chance of precipitation is 20%. A 20 percent chance of snow showers. Mostly cloudy, with a low around 23. Calm wind. A 30 percent chance of snow showers after noon. Mostly cloudy, with a high near 41. Calm wind becoming south southwest around 5 mph in the afternoon. Little or no snow accumulation expected.
Temperatures: 37 deg. F. 23 deg. F. 41 deg. F.
Wind direction: Calm Calm Calm
Wind speed:
Expected snowfall: 0 in. 0 in. 0 in.
For 8000-9000 ft.
  Friday Friday Night Saturday
Weather: Scattered snow showers after noon. Partly sunny, with a high near 26. Light and variable wind becoming west southwest around 6 mph in the afternoon. Chance of precipitation is 30%. Little or no snow accumulation expected. A 30 percent chance of snow showers, mainly before midnight. Mostly cloudy, with a low around 21. West wind around 6 mph. Little or no snow accumulation expected. A 50 percent chance of snow showers, mainly after noon. Mostly cloudy, with a high near 29. South southwest wind 5 to 9 mph. New snow accumulation of less than a half inch possible.
Temperatures: 26 deg. F. 21 deg. F. 29 deg. F.
Wind direction: WSE W SSW
Wind speed: 6 6 5-9
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.