THIS AVALANCHE ADVISORY EXPIRED ON January 27, 2018 @ 6:57 am
Avalanche Advisory published on January 26, 2018 @ 6:57 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

With the previous storm depositing a generous amount of snow and transport speed winds moving that snow around, there has been a lot of loading. We are forecasted to recieve even more snow with gusty winds, adding to this load. Avalanche danger will increase during the forecast period as the weekend storm systems roll through.  

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

With the previous storm depositing a generous amount of snow and transport speed winds moving that snow around, there has been a lot of loading. We are forecasted to recieve even more snow with gusty winds, adding to this load. Avalanche danger will increase during the forecast period as the weekend storm systems roll through.  

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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 Storm systems keep hitting the area with up to 30 inches of snow predicted by Sunday afternoon before the rain starts again. 

Avalanche Problem 2: Wind Slab
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The snow overnight was accompanied by transport speed winds as well as higher gusts predicted for during the day Friday through Saturday.  Expect to see extensive windslab and cornice formation throughout the forecast period and for them to become more reactive.

Avalanche Problem 3: Persistent Slab
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Multiple buried rain and sun crusts with weak snow exist in most locations. The dense snow we have been recieving with these current systems stress these weak layers, especially in areas of shallower snowpack.  Slope by slope assessment by digging is the only way to determine where these layers are.  

recent observations

We traveled up to the Elsie Lake area yesterday and observed extensive windloading, with transport occuring most of the time we were there.  Several naturals were observed from Wednesday, as well as reports from up North in the Selkirks. Stability tests were showing the storm slabs to be reactive (here).  With the new snow coming in, and little time for the snowpack to strengthen from the last storm, the danger will increase.  And don't forget the persistent layers, they are (unfortunately) a continuing theme to our forecasts this winter.  Don't start to become complacent now! Evaluate each slope you ski or ride to determine what's down there. When stability is in question, choose low angle terrain.  

Weather and CURRENT CONDITIONS
Weather observations from the Region
0600 temperature: 21 deg. F.
Max. temperature in the last 24 hours: 21 deg. F.
Average wind direction during the last 24 hours: WSW
Average wind speed during the last 24 hours: 8 mph
Maximum wind gust in the last 24 hours: 26 mph
New snowfall in the last 24 hours: 6-10 inches
Total snow depth: 62 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Spokane NWS
For 2000 ft. to 4000 ft.
Friday Friday Night Saturday
Weather: Snow showers Snow Snow
Temperatures: 30 deg. F. 26 deg. F. 33 deg. F.
Wind Direction: Southwest Southwest South
Wind Speed: 8-11 7 7-9
Expected snowfall: 2-4 in. 2-4 in. 2-4 in.
For 4000 ft. to 6000 ft.
Friday Friday Night Saturday
Weather: Snow showers snow snow
Temperatures: 23 deg. F. 22 deg. F. 29 deg. F.
Wind Direction: West Southwest South
Wind Speed: 17(G26) 10-15 13-16(G31)
Expected snowfall: 3-7 in. 2-4 in. 3-5 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.