THIS AVALANCHE ADVISORY EXPIRED ON December 17, 2019 @ 4:21 pm
Avalanche Advisory published on December 16, 2019 @ 4:21 pm
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

New precipitation from the weekend has settled, but don't become complacent out there. Most locations have depth hoar as well as a buried surface hoar layer that are still being reactive.  If you feel the snow settling or collapsing as you travel, that's a red flag to stick to the terrain under 30 degrees. We don't have much snow on top of these layers right now, but as the week brings more snow expect the danger to rise.  

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

New precipitation from the weekend has settled, but don't become complacent out there. Most locations have depth hoar as well as a buried surface hoar layer that are still being reactive.  If you feel the snow settling or collapsing as you travel, that's a red flag to stick to the terrain under 30 degrees. We don't have much snow on top of these layers right now, but as the week brings more snow expect the danger to rise.  

2. Moderate

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

2. Moderate

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

1. Low

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

We will unfortunately be talking about these layers for the foreseable forecasts, so best to pay attention from the beginning.  We have widespread depth hoar across the forecast area.  This can be seen when you dig down into the snow and find the sugary, loose crystals near the ground.  Many places also have a buried surface hoar layer.  Since our total snow depth isn't very deep right now, both these layers are prone to being triggered by a rider or slider.  And while it is getting harder and harder to trigger, think of the consequences!  Everything is rocky and has thin coverage right now.

recent observations

Last weekend's storm delivered some, but still not enough snow to make open country travel doable everywhere.  Lots of reports of core shots on skis and broken or bent sled skis from those who really had to get out.  Be careful out there folks!  Looks to be more precipitation coming this week. Remember that persistent weak layers tend to become more reactive during periods of rapidly changing weather such as new snow like we are forecast for Thursday. If you are out and about it is a good time to gather lots of spacial information for yourself.  Since the snow isn't very deep, it's easy to poke down and see what those layers are doing in your location at the different elevations and different aspects.  The more you know now, the better of you will be when more snow falls. And don't forget to send those observations in, they are helpful for all of us. 

 

Thanks again to Silver Mountain Ski Patrol this year for helping with observations for the Tuesday forecast.  Couldn't do it without them!

Weather and CURRENT CONDITIONS
Two-Day Mountain Weather Forecast Produced in partnership with the Spokane NWS
For 2000 ft. to 4000 ft.
Monday Monday Night Tuesday
Weather: Mostly Sunny Mostly Cloudy Mostly Cloudy then Slight Chance Snow
Temperatures: 34 deg. F. 24 deg. F. 35 deg. F.
Wind Direction: E E SE
Wind Speed: 5-7 6 5-7
Expected snowfall: 0 in. 0 in. 0 in.
For 4000 ft. to 6000 ft.
Monday Monday Night Tuesday
Weather: Mostly Sunny Mostly Cloudy Mostly Sunny
Temperatures: 29 deg. F. 18 deg. F. 27 deg. F.
Wind Direction: S S S
Wind Speed: 11-14, G28 14-17, G24 14-15, G21
Expected snowfall: 0 in. 0 in. 0 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.