THIS AVALANCHE ADVISORY EXPIRED ON February 13, 2020 @ 7:24 am
Avalanche Advisory published on February 12, 2020 @ 7:24 am
Issued by George Halcom - Payette Avalanche Center
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The Avalanche Hazard today is Moderate above 7,000 feet where winds have created large overhanging cornices and wind slabs that may be overlying crusts or buried weak layers. Below 7,000 feet the Avalanche Hazard is LOW. The Sun will soften the snow surface and may produce cornice failures and small natural point release avalanches during the day on slopes getting direct sunlight.

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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Winds have been doing a great job of moving the snow during this last storm cycle in just about every direction. During most of the wind activity, we saw some pretty warm temperatures. Since yesterday, we have been under a colder northern flow with pretty light winds. Any wind slab problems that you may encounter are going to be older, and probably not going to be very large. The colder temps should be helping the stiffer snow to bond.  

 

Avalanche Problem 2: Cornice
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As the Sun heats up the snow surface today, we there may still be some small natural cornice failures, and loose wet avalanche activity on slopes getting direct Sun, especially around rocks. There have been, small, fresh cornice and wind slab failures observed Tuesday on Council Mountain. Some of the cornices are so massive, and will allow you to get pretty far out over the edge of the ridge. Stay far back from the edges as they may fail, sending you on an involuntry ride.

The wind and Sun have effected and or strengthened the snow surface in the upper elevations over the last week. You might be able to get some snow moving easier on steep solar effected slopes, so pay attention to the aspect and move to cooler slopes that are not getting direct sunlight.

Avalanche Problem 3: Persistent Slab
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Natural avaalnches went off throughout the advisory area on a weak layer of buried surface hoar about a foot down Saturday-Sunday. Most of the activity was initiated by wind slab and cornice failures and was erased by the wind. It still may be possible to find some sensitive snow, but its trending more towards unlikely. Keep with your good travel protocols of spreading out on slopes that are steeper than 30 degrees.  

advisory discussion

*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, we toured up Granite Peak, near Council Mountain. The winds were strong and cold up on the ridges under bright Sun and blue skies. We observed some small fresh natural wind slab and cornice failures right below the ridges that happened around Saturday, some on a weak layer of buried surface hoar.  A lot of snowmobiles were traveling in steep terrain, and one set of high marks barely left a track in the firm wind effected East face of Council Mtn. Solar and wind effect was the theme with soft snow hiding lower in the shady protected areas.

 

Below are some Small natural avalanches that failed on buried surface hoar sometime around Saturday that we observed on East and North East aspects. 

 

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: 16 deg. F.
Max. temperature in the last 24 hours: 25 deg. F.
Average wind direction during the last 24 hours: Offline
Average wind speed during the last 24 hours: NA mph
Maximum wind gust in the last 24 hours: NA mph
New snowfall in the last 24 hours: NA inches
Total snow depth: NA inches
weather

Area Forecast Discussion
National Weather Service Boise ID
254 AM MST Wed Feb 12 2020

.SHORT TERM...Today through Saturday...A small tap of moisture
within the northwest flow will bring a few showers across the
central Idaho mountains, and along the Idaho/Nevada border
through the morning hours. Dry conditions expected by the
afternoon and will linger into Thursday. An approaching trough is
still expected on Thursday, though the bulk of moisture now looks
to be delayed further into the evening hours. Forecast continues
to reduce precipitation probabilities through the daytime hours of
Thursday. Models still agree that moisture will impact the area on
Friday, with the best coverage anticipated over the West Central
and Boise Mountains of Idaho. Snow levels with this initial
moisture push will drop to 2500 to 3500 ft by Friday afternoon.
Precipitation will wane on Friday evening, with a brief period of
drier conditions ahead of the next trough. Moisture will steadily
increase Saturday morning, with most areas seeing the potential
for some precipitation by Saturday afternoon. Snow levels for the
onset of moisture will be at valley floors on Saturday morning,
with levels increasing through the day. This will bring an
increasing presence of rain or a rain-snow mix for area valleys.
Snow accumulations with this Saturday push are expected to start
off light with 1 to 3 inches possible in the mountains.

.LONG TERM...Saturday night through Wednesday...Models remain
consistent by indicating a very moist and dynamic system poised to
continue to move through the forecast area through Sunday. Precip
water values continue to run in the 80-90th percentile, therefore
decent snow accumulations are possible. Snow levels rise from
near the valley floors to around 5500 near the Nv border Sunday
morning. Across the north, snow levels continue near the valley
floors. A northwest flow aloft continues into the PacNW Monday as
yet another system drops into the region bringing a continued
threat of snow showers especially over the west central mountains
in Idaho. The upper ridge out near 140W, begins to reamplify north
and east which begins to shut down any threat of precipitation
for midweek. Temperatures expected to remain at or slightly above
normal through the period.

&&

.AVIATION...Mainly VFR. Morning stratus clouds developing over
the region may bring periods of MVFR to the region. Surface winds
generally variable at less than 10 kts, with the exception of 15 kts
in the vcnty of KTWF. Winds aloft at 10K feet MSL north to northwest
15 to 30 kts.

 

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Wednesday Wednesday Night Thursday
Weather: Mostly sunny, with a high near 34. Calm wind. Partly cloudy, with a low around 14. Calm wind. Mostly sunny, with a high near 34. Southeast wind 3 to 6 mph.
Temperatures: 34 deg. F. 14 deg. F. 34 deg. F.
Wind direction: Calm Calm SE
Wind speed: 0 0 3-6
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Wednesday Wednesday Night Thursday
Weather: Mostly sunny, with a high near 24. North wind 6 to 8 mph. Partly cloudy, with a low around 14. Calm wind becoming south 5 to 7 mph after midnight. Mostly sunny, with a high near 26. South wind 9 to 14 mph.
Temperatures: 24 deg. F. 14 deg. F. 26 deg. F.
Wind direction: N Calm becoming South S
Wind speed: 6-8 5-7 9-14
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.