THIS AVALANCHE ADVISORY EXPIRED ON March 19, 2019 @ 6:12 am
Avalanche Advisory published on March 18, 2019 @ 6:12 am
Issued by George Halcom - Payette Avalanche Center
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The Avalanche Hazard will rise to Moderate as the Sun will increase the hazard throughout the day and heat up the snow, along with a warming trend which may produce cornice failures, rollerballs and wet-loose slides on steep solar influenced slopes.  Wind slabs are a possibility in upper elevation exposed terrain.  Be cautious, and avoid sunny steep slopes that are receiving an excessive amount of heat. 

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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Temperatures have been gradually rising each day, and are forecasted through the next week to be about 5-10 degrees above normal under clear sunny March skies. Each night, temperatures will dip back below freezing.  This melt-freeze cycle will stress and strengthen the snow pack.

Wet-loose avalanches have been going off the last few days, and are still possible. 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: Wind Slab
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Towards the end of the last storm, Northwest winds gusted upwards of 30 MPH pushing around about 4-6 inches of light snow creating shallow wind slabs that are sitting on crusts in places and were failing easily yesterday, while very shallow 1-2" deep, they do have the potential to sluff in steep, extreme northerly terrain.

Avalanche Problem 3: Cornice
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We have seen minimal cornice failure lately, but given 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. 

Yesterday, Some monster cornices on one of Bruin's North Faces.

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 ski toured the East aspect of Bruin. The melt-freeze trend, along with the snow coverage is allowing for some impressive travel. The snow pack was picking up quite a bit of heat, and produced some pretty good point releases on steep South slopes. The upper 2 inches on E and NE Bruin Between 7500ft and above consisted of a wind slab that we were able to get to sluff off on the very top 30 feet off of the summit on our first few turns.

Skiers should definitely 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 you break them?

 

 

 

 

 

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
327 AM MDT Mon Mar 18 2019

.SHORT TERM...Today through Thursday...A upper level ridge will
build across southwest Canada through the short term period,
bringing mostly clear skies, and warmer temperatures. Temperatures
will warm to around 5-10 degrees above normal, with the warmest
day on Wednesday. A trough off the CA coast will undercut the
ridge on Wednesday afternoon as it moves across the Great Basin on
Thursday. Showers will mainly be south along the Nevada border as
this system passes by into UT.

.LONG TERM...Thursday night through Monday...An upper trough off the
coast will move into the area by Saturday for a chance of showers
through Saturday night. Snow levels will be around 5000 feet. The
trough will exit the area to the east by Sunday for drier
conditions. The next upper trough may spread showers into the area
on Monday, although there are significant timing differences in the
models so confidence is low. Temperatures will be around 5 degrees
above normal on Friday and near normal Saturday through Monday.

&&

.AVIATION...VFR with mostly clear skies. Surface winds: Light mainly
east to around 10 kts. Winds aloft near 10k ft MSL: East 5-15 kts.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Monday Monday Night Tuesday
Weather: Sunny, with a high near 52. Calm wind becoming west northwest around 5 mph in the afternoon. Clear, with a low around 22. Northwest wind around 5 mph becoming calm. Sunny, with a high near 56. Calm wind.
Temperatures: 52 deg. F. 22 deg. F. 56 deg. F.
Wind direction: Calm-WNW NW-calm Calm
Wind speed: 5 5-0 0
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Monday Monday Night Tuesday
Weather: Sunny, with a high near 40. East northeast wind 6 to 14 mph. Clear, with a low around 28. East northeast wind 6 to 16 mph. Sunny, with a high near 44. Southeast wind 7 to 14 mph.
Temperatures: 28 deg. F. 22 deg. F. 32 deg. F.
Wind direction: SSE SE SSE-SW
Wind speed: 6 5-9 5-7
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.