THIS SNOWPACK SUMMARY EXPIRED ON December 17, 2017 @ 5:15 am
Snowpack Summary published on December 15, 2017 @ 5:15 am
Issued by Ben Bernall - Kootenai National Forest


bottom line:

 The good news is that we are in a period of LOW avalanche danger and our snowpack is currently very stable The bad news: We have a solid rain crust with a layer of facets (weak, sugary snow) and widespread surface hoar crystals growing on the snowpack.  If and when we get more snow we can expect a drastic decline in snowpack stability

Avalanche Character 1: Loose Dry
Loose Dry avalanches exist throughout the terrain, release at or below the trigger point, and can run in densely-treed areas. Avoid very steep slopes and terrain traps such as cliffs, gullies, or tree wells.

The upper 6-8" of the snowpack consists of poorly consolidated snow that is not bonded to the Thanksgiving rain crust.  In steep terrain this loose snow could knock a skier or rider off balance.  Though these sloughs are unlikely to bury you they could cause injury in high consequence terrain if trees and rocks are in your path of descent.

recent observations

On December 14th we travelled into the Keeler Rattle area where we found very stable snow conditions and some very impressive surface hoar development.  Snowpit stability tests revealed a stout rain crust at the bottom 2' of the snowpack, overlying this was a thin layer of facets covered by another layer of light powder.  We observed surface hoar as high as 6,000' in elevation on all aspects although it was much smaller and broken down in areas with a little exposure to wind and sun.  In some areas the crystals were up to 1.5" long.  Between the facet layer and this widespread surface hoar we will have alot of potential instabilities in the snowpack when snowy weather returns.

It's pretty on the surface!  But deadly when its buried.

weather summary
Backcountry Forecast from NWS Missoula issued:
500 AM MST Fri Dec 15 2017


A weak winter storm cycle will exist over the region for at least
the next week beginning Friday afternoon.

Snow levels will be just above valley elevations for much of the 
first system, with up to 8 inches total accumulation at pass 
elevations today through Saturday. Wind gusts over 40 mph along 
the Continental Divide will make backcountry travel difficult 
through tonight. Winds lighten up by Saturday midday.

The following storm system on Sunday- Monday will have similar 
snow and wind concerns along Continental Divide as well. A much 
colder pattern will arrive for the latter half of next week, 
however no significant breaks between mountain snows anticipated.


--------------------------- 5000-7000 FT ----------------------------
                      Today        Tonight      Sat      
Cloud Cover           90%          90%          75%      
Hi/Lo Temps           26 to 31     17 to 21     21 to 28 
Winds(mph)            SW 15G32     W  6G18      W  5     
Precip Chc            100          60           30       
Precip Type           snow         snow         sno/shr  
Liquid Amt            0.12         0.10         0.01     
Snow Ratio(SLR)       13:1         17:1         18:1     
Snow Amt(in)          1-2          1-3          0        

Snow Level            1500         1500         1000     


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.