THIS AVALANCHE ADVISORY EXPIRED ON March 17, 2018 @ 6:29 am
Avalanche Advisory published on March 16, 2018 @ 6:29 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

Spring skiing and spring avalanche problems? Visit the SW -S- SE solar aspects. Heads up for roller balls, pinwheels, cornice falls, and natural wet slides as the day warms up to indicate the instability is rising.  Winter skiing and winter avalanche problems? Visit the NE - N - NW aspects. Heads up for lingering windslabs and always be checking for the persistent weak layers.  

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

Spring skiing and spring avalanche problems? Visit the SW -S- SE solar aspects. Heads up for roller balls, pinwheels, cornice falls, and natural wet slides as the day warms up to indicate the instability is rising.  Winter skiing and winter avalanche problems? Visit the NE - N - NW aspects. Heads up for lingering windslabs and always be checking for the persistent weak layers.  

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: Loose Wet
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Watch for instability and the potential for loose wet slides to increase as solar loading increases during the day.  Precipitation in the form of rain will also cause the risk for wet slides to increase.  Pay attention to above you and watch for cornices. They become more unstable as the temperatures rise.  

Avalanche Problem 2: Persistent Slab
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The cool, clear nights last weekend left us with a surface hoar layer that got buried in the storms earlier this week.  While it doesn't have much weight on it right now, it could become problematic as more dense precipitation comes in over the weekend.  Also, our February persistent weak layer is still down there right around a meter deep on the North sides and 60 to 80cm deep on the south sides. It remains important for you to dig down at your location to assess the stability before committing to avalanche terrain.    

recent observations

We visited the FAA towers yesterday and found a variety of conditions to meet everyones needs!  Spring skiing is all about working the elevations and the aspects.  Overall the pits were showing good stability but it is worth noting that the persistent weak layers behaved differently every where we tested them.  It is still important to assess each slope you are thinking about riding or sliding to check for the stability of those layers.  We didn't observe any new windslabs and Silver Mountain hasn't reported any forming on the ridgetops there. The clouds lifted around noon, and pinwheels were immediately starting to form.  It doesn't take much solar loading to cause a decrease in the snowpack stability!

Weather and CURRENT CONDITIONS
Weather observations from the Region
0600 temperature: 25 deg. F.
Max. temperature in the last 24 hours: 33 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 5 mph
Maximum wind gust in the last 24 hours: 7 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 79 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Spokane NWS
For 2000 ft. to 4000 ft.
Friday Friday Night Saturday
Weather: Mostly Sunny Chance rain/snow then chance snow showers Chance rain/snow then chance showers
Temperatures: 46 deg. F. 29 deg. F. 43 deg. F.
Wind Direction: NE Ne NE
Wind Speed: 5-7 6 5-7
Expected snowfall: 0 in. <.5 in. <.5 in.
For 4000 ft. to 6000 ft.
Friday Friday Night Saturday
Weather: Slight chance of snow showers then chance rain/snow chance snow showers chance snow showers then rain/snow likely
Temperatures: 36 deg. F. 26 deg. F. 34 deg. F.
Wind Direction: SE E E
Wind Speed: 6 5-7 6
Expected snowfall: <.5 in. <.5 in. <.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.