THIS AVALANCHE ADVISORY EXPIRED ON December 29, 2017 @ 8:55 pm
Avalanche Advisory published on December 28, 2017 @ 8:55 pm
Issued by Eric Morgan - Idaho Panhandle Avalanche Center

Selkirks/Cabinets

bottom line

Red flags are evident with increasing and recent snowfall moderate to heavy, breezy and gusty winds, observed whumphing.  With the continued precipitation and warming temperatures expect more weight and strain our persistent weak layers 2-3 feet down in the snowpack.  Expect to see some natural avalanche activity and whumphing and cracking the next few days until things settle.  

How to read the advisory

Selkirks/Cabinets

How to read the advisory

Red flags are evident with increasing and recent snowfall moderate to heavy, breezy and gusty winds, observed whumphing.  With the continued precipitation and warming temperatures expect more weight and strain our persistent weak layers 2-3 feet down in the snowpack.  Expect to see some natural avalanche activity and whumphing and cracking the next few days until things settle.  

4. High

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Above Treeline
Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.

3. Considerable

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Near Treeline
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.

2. Moderate

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Below Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
    Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
Avalanche Problem 1: Storm Slab
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Recent precipitiation 1-2 feet with winds and increasing temperatures has created some slab formation on all upper elevations and exposed ridgetops.  The winds have been shifty coming out of SW, W, NW, with todays winds out of the N helping all aspects slab up with up to 7 more inches expected today.   

Avalanche Problem 2: Wind Slab
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Ridgetop winds have been out of the S, SW with current winds out of the NW 11MPH and becoming  N today combined with  moderate to heavy snowfall.  This will allow slab formation and reverse loading.  

recent observations

In the Selkirks yesterday, Kevin Davis and I found 6 inches of fresh on last weeks 2' of storm snow.  The precipitation intensified in the afternoon and is expected to continue through tonight.  At 5500 feet on a North aspect we found 4 feet of snow with 2 feet of soft snow on surface hoar and faceted snow that sits on the Thanksgiving crust that is about a foot thick.  Travelling in the mountains was challenging with alot of trailbreaking and some downed timber off machine groomed trails.  Our compression tap tests went on an 8 on the fresh 6" storm snow and a 12 on the surface hoar.  Expect it to become more reactive with a quick load of weight on it.  

Weather and CURRENT CONDITIONS
weather summary
Today
Snow. The snow could be heavy at times. Temperature falling to around 19 by 5pm. Northwest wind around 10 mph becoming northeast in the afternoon. Chance of precipitation is 100%. Total daytime snow accumulation of 3 to 7 inches possible.
Tonight
Snow. The snow could be heavy at times. Low around 18. Northeast wind 10 to 16 mph becoming south after midnight. Chance of precipitation is 100%. New snow accumulation of 6 to 10 inches possible.
Saturday
Snow, mainly before 10am. Temperature rising to near 23 by 11am, then falling to around 17 during the remainder of the day. Breezy, with a southwest wind 13 to 22 mph, with gusts as high as 36 mph. Chance of precipitation is 90%. New snow accumulation of 1 to 2 inches possible. ......  Spokane Weather Service 
Weather observations from the Region
0600 temperature: 28 deg. F.
Max. temperature in the last 24 hours: 28 deg. F.
Average wind direction during the last 24 hours: 290
Average wind speed during the last 24 hours: 30 mph
Maximum wind gust in the last 24 hours: 50 mph
New snowfall in the last 24 hours: 8 inches
Total snow depth: 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.