THIS AVALANCHE ADVISORY EXPIRED ON February 8, 2020 @ 6:43 am
Avalanche Advisory published on February 7, 2020 @ 6:43 am
Issued by Kevin Davis - Idaho Panhandle Avalanche Center

Selkirks/Cabinets

bottom line

The upper two feet of the snowpack is riddled with crusts now due to the wildly changing temperatures since mid-January. There are some weak layers that could be problematic where they are buried deeper or get buried deeper after the next round of snow.

How to read the advisory

Selkirks/Cabinets

How to read the advisory

The upper two feet of the snowpack is riddled with crusts now due to the wildly changing temperatures since mid-January. There are some weak layers that could be problematic where they are buried deeper or get buried deeper after the next round of snow.

2. Moderate

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Above Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

2. Moderate

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Near Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

1. Low

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Below Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
    Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Normal Caution
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Numerous storms since mid-January have contributed to the layering of snow in the upper two feet of our snowpack.  Unlike the three feet of consistent powder we got in early January the precipitation we have been getting for the past few weeks has gone from rain to snow and back.  This has left us with a layercake of crusts and loose snow all resting above the thick crust from Mid-January. We saw some weak layers above and below the crusts in our pit tests yesterday on Trestle Ridge in the Cabinets. You'll want to use more caution on windloaded slopes below ridgelines where the slabs could be more touchy. We could easily get shooting cracks in this layer by skiing above our partners tracks but the failure did not propagate far. That could change with the new snow in the forecast. It is a layer of powder snow sandwiched between a thicker crust below and a thin breakable crust above.   Read on.

Avalanche Problem 2: Storm Slab
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I'm including storm slab as an avalanche problem in todays advisory to give our snowgoers a heads up that new snow forecast tonight on our current snowpack will create some stability issues. The weak layer we are watching is a layer of powder snow between the hard crust from last Sunday and a thin breakable crust on top that formed mysteriously two nights ago.  It shears easily and we can get it to fail when we ski across it, so we know its weak.  There is just not enough snow stressing it yet.  Load this weak layer up with new snow and blowing snow and you'll create a problem.  So, be heads up when you get into the high country on Saturday because this layer could be touchy but expect it on easterly aspects below treeline and on all aspects up higher.  The avalanche hazard could rise to Considerable for the weekend depending on the amount of snowfall and wind.

advisory discussion

The deadline for the Doug Abromeit Avalanche Scholarship is coming up on February 28th.  If you're 14-24 years old you could win your spot in a level 1 avalanche class next year for free.  Go to our education page for details.

recent observations
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While traveling around Trestle Ridge yesterday we found very challenging sliding conditions. We were breaking through multiple crust layers with our skis.  The conditions were easier on open slopes where the snow was undisturbed. Under the trees the snow was icy and chunky from the wet snow that had fallen from the branches. My feeling about this weak layer is that it will hold up longer to loading from the new snow since it is under a crust that will have some tensile strength to keep it from propagating a fracture.  The thing that changes that equation is you starting the crack by breaking through the crust.  If it gets touchy with alot of new snow and wind deposition you might not get the normal signs of natural avalanches, whumphing, and shooting cracks. So hammer on lots of safe features to see how touchy this weak layer is.

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Weather and CURRENT CONDITIONS
weather summary 
SYNOPSIS...
Another storm system will arrive tonight into Saturday. This one
will bring mainly valley rain and mountain snow, but also result
in a period of breezy to windy conditions into Saturday. After a
few dry days, a weak system on Tuesday may bring more
precipitation, followed by mainly dry weather for Wednesda
Weather observations from the Region
0600 temperature: 24 deg. F.
Max. temperature in the last 24 hours: 27 deg. F.
Average wind direction during the last 24 hours: ENE
Average wind speed during the last 24 hours: 1 mph
Maximum wind gust in the last 24 hours: 1 mph
New snowfall in the last 24 hours: 1 inches
Total snow depth: 112 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Spokane NWS
For 2000 ft. to 4000 ft.
Friday Friday Night Saturday
Weather: A 30 percent chance of snow after 10am. Patchy fog before 10am. Otherwise, mostly cloudy. Snow. Chance of precipitation is 100%. Snow showers likely, mainly before 10am, then a chance of snow after 4pm. Mostly cloudy. Chance of precipitation is 60%.
Temperatures: 31 deg. F. 40 deg. F. 39 deg. F.
Wind Direction: S S SW
Wind Speed: 5-7 7-16 6-10 becoming NE
Expected snowfall: <1 in. 1-3 in. <1/2 in.
For 4000 ft. to 6000 ft.
Friday Friday Night Saturday
Weather: Snow, mainly after 4pm. Chance of precipitation is 80%. Snow. The snow could be heavy at times. Wind chill values as low as zero. Windy. Chance of precipitation is 100%. Snow showers likely, mainly before 10am, then a chance of snow after 4pm. Wind chill values as low as zero. Windy. Chance of precipitation is 70%.
Temperatures: 29 deg. F. 19 deg. F. 27 deg. F.
Wind Direction: NW S SW
Wind Speed: 8-17mph becoming south in afternoon. 21-26mph increasing to 34mph. Gusting to 48mph 21-26mph gusting to 37mph.
Expected snowfall: 1 in. 5-9 in. 1-3 in.
Disclaimer

Avalanche conditions change for better or worse continually. Backcountry travelers should be prepared to assess current conditions for themselves, plan their routes of travel accordingly, and never travel alone. Backcountry travelers can reduce their exposure to avalanche hazards by utilizing timbered trails and ridge routes and by avoiding open and exposed terrain with slope angles of 30 degrees or more. Backcountry travelers should carry the necessary avalanche rescue equipment such as a shovel, avalanche probe or probe ski poles, a rescue beacon and a well-equipped first aid kit.  For a recorded version of the Avalanche Advisory call (208)765-7323.