THIS AVALANCHE ADVISORY EXPIRED ON December 14, 2019 @ 6:30 am
Avalanche Advisory published on December 13, 2019 @ 6:30 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

New snow and winds overnight fell onto a shallow snowpack that hasn't had time to adjust.  Hiding just underneath this new snow is a buried surface hoar layer that was proving to be reactive yesterday, especially in windblown areas.  As we don't have enough snow to ski and ride yet in the lower elevations, today's forecast is for only above treeline. 

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

New snow and winds overnight fell onto a shallow snowpack that hasn't had time to adjust.  Hiding just underneath this new snow is a buried surface hoar layer that was proving to be reactive yesterday, especially in windblown areas.  As we don't have enough snow to ski and ride yet in the lower elevations, today's forecast is for only above treeline. 

3. Considerable

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

No Rating

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Near Treeline

No Rating

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Below Treeline
    Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Wind Slab
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The main areas of concern are windloaded slopes, where the snow has been deposited and stiffened into a harder slab on top of the underlying snow.  Double your trouble because of the buried surface hoar layer lurking underneath the new snow.  Look for chalky appearing snow that is pillowed. 

Avalanche Problem 2: Persistent Slab
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It's early season and you may be thinking "oh no, not again", but persistent slabs are a very common problem in the early season.  The storm from Wednesday through today burried a surface hoar layer that has crystals up to 4 mm in size (that's large!) that is resting on top of an ice crust layer.  This was found to be widespread, so you aren't safe on certain aspects yet.  Yesterday it was reactive in tests and with additional loading from last night, especially in areas of windloading, I expect this to become more sensitive to human triggers. We will be paying attention to this layer

recent observations

My main concern right now is more in the broken leg realm of getting to any snow that is worth skiing! I wouldn't even contemplate going cross country on a snowmobile yet, stick to the logging roads! If you do manage to get to snow, be safe and use all your avalanche prowness.  Don't get sucked into riding something just because the winter pow bug has hit so bad. The areas that look the best to ride and have the most coverage are the ones that have had additional windloading to help fatten them out. Maybe take a look up to our northern forecast areas, they have faired better in the snow accumulation than we have. 

 
Weather and CURRENT CONDITIONS
Two-Day Mountain Weather Forecast Produced in partnership with the Spokane NWS
For 2000 ft. to 4000 ft.
Friday Friday Night Saturday
Weather: Snow Likely Snow Likely Chance Snow
Temperatures: 26 deg. F. 23 deg. F. 25 deg. F.
Wind Direction: SW SW W
Wind Speed: 10-15 6 6-8
Expected snowfall: 1-3 in. 1 in. 1 in.
For 4000 ft. to 6000 ft.
Friday Friday Night Saturday
Weather: Snow Likely and Patchy Blowing Snow Snow Likely Chance snow
Temperatures: 25 deg. F. 21 deg. F. 23 deg. F.
Wind Direction: SW SW W
Wind Speed: 15-25, G36 8-10 10-13
Expected snowfall: 3-5 in. 1-2 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.