THIS AVALANCHE ADVISORY EXPIRED ON January 18, 2020 @ 6:17 am
Avalanche Advisory published on January 17, 2020 @ 6:17 am
Issued by Kevin Davis - Idaho Panhandle Avalanche Center

Selkirks/Cabinets

bottom line

There is alot of new snow out there. You'll find deep powder conditions on all aspects. Watch for weak layers in the upper two to three feet, some may be associated with windslabs. We did to find anyting too nasty in the last weeks storm snow.  Normal caution is advised.

How to read the advisory

Selkirks/Cabinets

How to read the advisory

There is alot of new snow out there. You'll find deep powder conditions on all aspects. Watch for weak layers in the upper two to three feet, some may be associated with windslabs. We did to find anyting too nasty in the last weeks storm snow.  Normal caution is advised.

2. Moderate

?

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

2. Moderate

?

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

1. Low

?

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: Storm Slab
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

On a NW aspect in the Cabinet Mountains yesterday we found about two feet of loose, unconsolidated new snow over one foot of denser new snow from the past week. A couple weak interfaces popped out in our compression tests but the asscociated slabs did not have the cohesion to create a slab.  The snow is too fluffy right now.  What a problem to have... Where you might find this layer more sensitive is where the surface layer is wind effected.  Read on...

Avalanche Problem 2: Wind Slab
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

With much effort, we made it to the ridge. We passed through some wind effected snow and it released in a slab. On top, we saw some good cornice formation but even the cornices are to loose to get them to fail as a large chunk. Windslabs do exist and they could be on multiple aspects and they will be more sensitive than the surrounding snow. Watch for isolated pockets of denser windslabs especially on exposed slopes. They seem to be limited to the upper elevations right now.

Avalanche Problem 3: Persistent Slab
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Eric and I did not dig down 7 feet to the buried persitent weak layer of surface hoar. We are assuming it is still intact and identifiable. We'll try to pinpoint this layer next week. What you should know and how you should conduct yourself knowing there may be a nasty weak layer buried 7 feet deep in the pack is that it will take a whole lot of stress to get this layer to fail, but when it does, it goes big and you had better not be on it. Places where you might screw up with regard to this layer are bigger terrain features like large convex slopes with no toe support, complex terrain with alot of snow depth variation, and high elevation planar slopes with little anchoring. We're starting to build up a good base and all this wieght from new snow will start to compress the buried weak layer. With patience and more snow, it should go away. Be patient. Those big slopes will still be there.

advisory discussion

If you are between the ages of 14 and 24, or know someone who is, and are looking to increase your avy saavy, then we have a deal for you.  The Doug Abromeit Avalanche Scholarship has sent 6 recipients to a free level 1 avalanche class so far.  You could be the next.  You have until February 28th to write a one page essay about why you should be selected and how you would use this education to increase avalanche awareness. Go to our Eduacation page and Click on Doug Abromeit Avalanche Scholarship.  Good Luck!

recent observations

Deep powder was my most obvious observation. Off trail riding was tough since we had trail sleds yesterday and the trail breaking was deep. Snow density near the top was very light, for North Idaho, at 12 - 15%. We did not see any avalanche activity. Any weak layers in the new snow did not have a dense enough slab on top to propagate a fracture and start an avalanche. So, for now the conditions are great for deep powder sliding. This light snow will settle with time and we could develop some slabby conditions in the future that could give us problems.  The weather is ecpected to warm a little so watch the surface snow conditions over the weekend.

Weather and CURRENT CONDITIONS
weather summary

Today you can expect partly sunny conditions with highs in the mid teens and maybe some winds as one storm exists and the next slides in. Temperatures will be on the rise this weekend but hopefully not enough to ruin our great powder conditions.

Weather observations from the Region
0600 temperature: 19 deg. F.
Max. temperature in the last 24 hours: 24 deg. F.
Average wind direction during the last 24 hours: calm
Average wind speed during the last 24 hours: calm mph
Maximum wind gust in the last 24 hours: calm mph
New snowfall in the last 24 hours: 2 inches
Total snow depth: 132 inches
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.