THIS AVALANCHE ADVISORY EXPIRED ON February 9, 2020 @ 7:33 am
Avalanche Advisory published on February 8, 2020 @ 7:33 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 likely today throughout our forecast area. A combination of heavy snowfall,  winds gusting to 50+mph and warm temperatures have created dangerous avalanche conditions. Many natural and human caused storm slabs occurred over the last 3 days in the new snow layers.  Some of these avalanches were also releasing on weak layers created prior to the storm.  Today is NOT the 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: 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 have already topped 50 mph this morning.  Lighter cooler snow falling through the day today will increase the ability of the wind to transport snow and build new wind slabs.  The addition of wind slabs to our list of avalanche problems will rapidly increase the density of the slab and up the consequences of triggering an avalanche in wind affected terrain.  Avoid traveling near ridgelines or in areas where you can see or feel a change in the surface or density of the snowpack.  Obvious clues like ripples, drifts, or cracks shooting out from your skis or sled mean you should move to more wind protected terrain.

Avalanche Problem 2: Storm Slab
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Local snotel sites picked up just shy of 4 inches of Snow Water Equivalent since Tuesday.  Brundage Mountain Resort is reporting 44 inches since Tuesday.  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 last night will add to the problem especially in the upper elevations.  Another round of snow today will add close to another foot in the upper elevations by tomorrow.  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 have seen widespread avalanches earlier this week and today we will be adding more storm snow and windblown snow to an already sensitive snowpack today. Natural and human triggered avalanches  releasing anywhere from 1-4 feet deep  are likely 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, don't travel alone, keep your eyes on your partners and stay off the steeps today.

Avalanche Problem 3: 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 Thursday that also was able to propagate around several small ridges and knobs. See the observation and description he posted on our recent observation page.

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 and limited visibility were the theme on Thursday and Friday.  A widespread natural avalanche cycle occurred on Thursday with some human caused avalanches also reported.  Yesterday was the warmest day of the storm cycle and we observed wet loose activity in the afternoon.  Lower elevations did see a mixture of snow and rain at times.  Cooler temperatures overnight last night and a more moderate day today will help the snow "set up" and begin to heal as temperatures cool off over the next few days.  Winds were light yesterday but overnight ramped up.  With high winds and wet snow, expect to see some inverted snow conditions with heavy snow resting on some of the lighter snow below.

Also, as a heads up, not all snowmobile trails have been groomed in the last few days.  The County Groomers are concentrating on the main routes and routes close to the popular parking areas. Grooming stops at the Association Cabin meadow north of Goose Lake on the Goose Lake Rd.  If the groomer has not been on a trail, you are going to need at least an 800 mountain sled to break trail.  Trail sleds and beginner riders will find conditions challenging in many places.

If you see or trigger an avalanche today, PLEASE take the time to add it into our observations page.  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: 17 deg. F.
Max. temperature in the last 24 hours: 28 deg. F.
Average wind direction during the last 24 hours: NA
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

.SHORT TERM...Today through Tuesday...An upper trough entering the
Pacific NW this morning, will continue on a southeastward track
today. An accompanying cold front which is approaching Baker City
at 10Z this morning will reach the ID/NV border by late morning.
A narrow band of showers will accompany the frontal passage across
much of the area, only dissipating as the front pushes into the
western Magic Valley. Cold, unstable air aloft behind the front
will support continued shower development this afternoon/evening
across higher terrain with less coverage in the valleys. Snow
levels will drop through the day with accumulations of 1-2 inches
in mountain valleys and up to 5 inches across higher mountains.
Lower valleys will see rain or rain/snow mix with the frontal
passage and any afternoon shower activity. West-northwest winds
ramp up this afternoon across southeast Oregon and through the
Snake Plain with gusts to 40 mph possible. A dry air mass will
become established over the region Sunday, and persist into early
next week as an upper ridge expands onto the coast. A slight
chance of showers exists over w-central Idaho mountains on Tuesday
for the passage of a shortwave trough, though there is
uncertainty on the timing of this system. Temperatures will be
near normal through Tuesday.

.LONG TERM...Tuesday night through Friday...A slight threat of
snow showers remain possible Wednesday as a moist northwest flow
aloft continues Wednesday. Otherwise, the extended models continue
in good agreement indicating that the upper ridge retrogrades
westward and gets suppressed southward by the end of the week as a
much stronger system pushes into the PacNW Thursday and into the
region Friday morning. Snow levels should be down to the valley
floors. Yet another system pushes into the region Saturday
continuing the threat of snow showers for all areas. Temperatures
remaining near or slightly above normal through most of the
period, potentially becoming slightly below normal for the
weekend.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Saturday Saturday Night Sunday
Weather: Snow showers. High near 32. Southwest wind 6 to 11 mph, with gusts as high as 21 mph. Chance of precipitation is 80%. Total daytime snow accumulation of 1 to 2 inches possible. A 40 percent chance of snow showers before 11pm. Mostly cloudy, then gradually becoming mostly clear, with a low around 21. North wind 3 to 6 mph. New snow accumulation of less than a half inch possible. Sunny, with a high near 32. North northwest wind around 6 mph becoming calm.
Temperatures: 32 deg. F. 21 deg. F. 32 deg. F.
Wind direction: SW N NNW
Wind speed: 6-11, Gusts to 21 3-6 6
Expected snowfall: 1-2 in. Trace in. 0 in.
Granite Mountain at 7700 feet.
  Saturday Saturday Night Sunday
Weather: Snow showers. High near 21. West wind 9 to 14 mph. Chance of precipitation is 100%. Total daytime snow accumulation of 3 to 7 inches possible. Snow showers before 11pm. Low around 13. West northwest wind 8 to 10 mph becoming north in the evening. Winds could gust as high as 21 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 3 inches possible. Mostly sunny, with a high near 22. North wind 7 to 9 mph.
Temperatures: 21 deg. F. 13 deg. F. 22 deg. F.
Wind direction: W WNW N
Wind speed: 9-14 8-10, Gusts to 21 7-9
Expected snowfall: 3-7 in. 1-3 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.