THIS AVALANCHE ADVISORY EXPIRED ON February 8, 2020 @ 7:19 am
Avalanche Advisory published on February 7, 2020 @ 7:19 am
Issued by Dave Bingaman - Payette Avalanche Center
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The Avalanche Hazard is HIGH today.  Natural and Human triggered avalanches will be very likely today throughout our forecast area. A combination of heavy snowfall, increasing temperatures and moderate winds have created dangerous avalanche conditions. Many natural and human caused storm slabs were occurring yesterday in the new snow layers.  Some of these avalanches were also releasing on weak layers created prior to the storm.  Today is NOT a day for skiing or riding steep terrain.

How to read the advisory


  • Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
Avalanche Problem 1: Storm Slab
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Local snotel sites picked up just shy of 3.5 inches of Snow Water Equivalent in the last 72 hours.  Brundage Mountain Resort is reporting 37 inches of snow since Tuesday.  Yesterday we saw between 37 and 40 inches of unconsolidated snow between 6800 and 7200 feet. Overnight we picked up an additional 9 inches of snow in the mountains. All of this adds up to a LOT of snow in a relatively short period of time.  Temperatures have been increasing steadily with this storm and the snow that was soft, cold and unconsolidated is turning into a warmer, more cohesive slab.  Increasing winds today and tonight will add to the problem especially in the upper elevations.  A combination of crusts and weak layers made up of preserved surface hoar and near surface facets are underlying the new snow in many places allowing avalanches to propagate over larger areas.

We saw widespread natural avalanches yesterday in the Goose Lake and Fisher Creek areas.  Today, we will be adding yet more snow(weight) to an already sensitive snowpack. Expect to see natural and human avalanches  releasing anywhere from 1-4 feet deep through the day today.  We have multiple red flags waving in the mountains right now as well as some challenging, not for beginners deep snow travel conditions.  

If you are a skier, spend the day at one of the local resorts. If you are a sledder, travel with a friend, keep your eyes on your partners and stay off the steeps today.

Avalanche Problem 2: Persistent Slab
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A combination of weak layers was distributed last week and at the beginning of this week.  Melt freeze and sun crusts from last week's warmup followed by a 20 degree cool down formed on lower elevation slopes and slopes that got hit by the sun last week.  In addition,  a thin layer of surface hoar and near surface facets formed during the very cold, clear weather that followed the warmup.  We found some evidence of preserved surface hoar earlier this week in our pits.  Yesterday, the character of the avalanches we saw indicated a buried surface hoar layer that was able to propagate between features.  We were able to see a thin layer of fragmented surface hoar while inspecting the crowns of some of these avalanches. These were in wind protected areas below 7500 feet.  A snowmobiler triggered an avalanche in the Twin Lakes area yesterday that also was able to propagate around several small ridges and knobs. See the observation and description he posted on our recent observation page.

Avalanche Problem 3: Wind Slab
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Winds accompanying the storm over the last few days have been relatively light.  Wind speeds started to increase last night and will continue today,  gusts will be getting into the 30 mph  range tonight.  The addition of wind slab problems to our list of avalanche problems will increase the density of the slab and up the consequences. Avoid traveling near ridgelines or in areas where you can see or feel a change in the surface or density of the snowpack.

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 traffic.

recent observations

Deep snow hindered our ability to get far from roads yesterday but we were able to observe plenty of avalanche activity in the Goose Lake and Fisher Saddle areas.  Most of the steep road cuts had failed between the Titus parking lot and Goose Lake as well as along the Fisher Saddle Road.  We ran into the county groomer on the Fisher Road and he was able to trigger small avalanches along all of the steep road cuts with the cat in this area as well.  Numerous natural avalanches could be seen on steep slopes on all aspects.  Hasty pits revealed buried crusts and preserved weak layers in many areas. Heavy snowfall was the theme of the day with intervals of snow exceeding 1 inch per hour at times. 

If you see or trigger an avalanche today, PLEASE take the time to add it into our observations pag.  It is simple, takes only a couple of minutes and the form prompts you for the pertinent info.  The info you share may help save a life.

  

CURRENT CONDITIONS Today's Weather Observations From the Granite Weather Station at 7700 ft.:
0600 temperature: 26 deg. F.
Max. temperature in the last 24 hours: 27 deg. F.
Average wind direction during the last 24 hours: NE
Average wind speed during the last 24 hours: 7 mph
Maximum wind gust in the last 24 hours: 23 mph
New snowfall in the last 24 hours: NA inches
Total snow depth: NA inches
weather

.SHORT TERM...Today through Monday...Moist northwest flow will
gradually relent today in response to an approaching upper level
trough. Mountain valleys that held onto the snow and cold air on
Thursday are showing signs of warming early this morning, and that
trend will continue today. Periods of heavier precipitation will
bring minor accumulations to mountain valleys this morning but by
late morning sites below 5500 feet will change to rain. Higher
elevations will continue to see moderate snowfall with another 2
to 5 inches through this afternoon. Lower elevations remain dry
today with relatively mild temperatures. The surface pressure
gradient and flow aloft will continue to support gusty west winds,
especially across the middle Snake Plain and higher terrain to
the south, both areas where criteria for a wind advisory will be
met. The shortwave trough and accompanying cold front will drop
through the Pacific NW Friday night into Saturday. Mountains will
see a round of snow with the passage of this wave while valleys
below 4500 feet see rain or rain/snow mix with little if any
accumulation. Gusty winds and cooler temperatures follow the
passage of the front on Saturday, and northerly flow will keep the
colder temperatures in place for Sunday while winds slacken some.
Any lingering showers taper off on Sunday as a ridge builds in
from the coast. The ridge expands inland on Monday keeping dry
conditions over the region and modifying temperatures a few
degrees.

.LONG TERM...Monday night through Thursday...ECM/GFS and Canadian
all in good agreement by indicating an upper high near
40n130W/135W through a majority of the extended period. This would
tend to keep a fairly low impact weather pattern over the region,
except over far northeastern portion of Valley County where a
threat of snow showers are possible. This as weather systems move
over the ridge and into the central portions of the US.
Deterministic models diverge by Friday, but each models ensemble
forecast indicates that the ridge retrogrades slightly westward to
around 140W. This brings a better threat of snow showers to the
region. Temperatures at or slightly above normal through the
forecast period with generally light winds.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Friday Friday Night Saturday
Weather: Rain and snow. High near 37. South southwest wind around 8 mph. Chance of precipitation is 100%. Total daytime snow accumulation of around an inch possible. Rain and snow likely, mainly after 11pm. Snow level 5200 feet. Cloudy, with a low around 26. South wind 5 to 11 mph, with gusts as high as 26 mph. Chance of precipitation is 70%. New snow accumulation of less than a half inch possible. Snow. High near 32. West southwest wind 7 to 14 mph, with gusts as high as 33 mph. Chance of precipitation is 100%. New snow accumulation of 1 to 3 inches possible.
Temperatures: 37 deg. F. 26 deg. F. 32 deg. F.
Wind direction: SSW S WSW
Wind speed: 8 5-11 7-14, Gusts to 33
Expected snowfall: Trace in. Trace in. 1-3 in.
Granite Mountain at 7700 feet.
  Friday Friday Night Saturday
Weather: Snow. High near 28. West wind 7 to 10 mph. Chance of precipitation is 100%. Total daytime snow accumulation of 3 to 5 inches possible. Snow, mainly after 11pm. Steady temperature around 27. South southwest wind 8 to 17 mph, with gusts as high as 31 mph. Chance of precipitation is 90%. New snow accumulation of 1 to 3 inches possible. Snow. High near 22. West southwest wind 9 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 100%. New snow accumulation of 3 to 5 inches possible.
Temperatures: 28 deg. F. 27 deg. F. 22 deg. F.
Wind direction: W SSW WSW
Wind speed: 7-10 8-17, Gusts to 31 9-15, Gusts to 30
Expected snowfall: 3-5 in. 1-3 in. 3-5 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.