THIS AVALANCHE ADVISORY EXPIRED ON March 21, 2018 @ 6:38 am
Avalanche Advisory published on March 20, 2018 @ 6:38 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

Isolated windslabs formed Sunday night and yesterday morning: look for pillowy looking snow.  Use caution in steep, unsupported terrain on the E-NE-N aspects where windslabs will still be lingering today.  As the temperatures go up with the sunshine today, expect to see pinwheels, rollerballs, and loose wet slides.  

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

Isolated windslabs formed Sunday night and yesterday morning: look for pillowy looking snow.  Use caution in steep, unsupported terrain on the E-NE-N aspects where windslabs will still be lingering today.  As the temperatures go up with the sunshine today, expect to see pinwheels, rollerballs, and loose wet slides.  

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: Wind Slab
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Winds Sunday night and into Monday morning have left windslabs near the ridgelines at the upper elevations. 

Avalanche Problem 2: Loose Wet
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As the sun comes out today, expect to see pinwheels, rollerballs, and loose wet slides in steep terrain on the Southern aspects. These are red flags that the snowpack has become unstable and an indicator to step off steep terrain. Expect to see the instability rise at the lower elevations on all aspects as well as the temperature goes up.  Northerly aspects at the higher elevations should still harbor colder snow.  

Avalanche Problem 3: Persistent Slab
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In some locations, there are now two buried surface hoar layers from this last week.  Both have been reactive in pit tests, showing off a Q1 clean sliding surface with moderate force.  And there is still the February buried layer.  As usual, it is important for you to assess each location you plan on riding for these layers by getting down and digging in the snow.  

recent observations

Thank you Silver Mountain with helping out with observations and pit data yesterday. 

Weather and CURRENT CONDITIONS
Weather observations from the Region
0600 temperature: 23 deg. F.
Max. temperature in the last 24 hours: 28 deg. F.
Average wind direction during the last 24 hours: WSW
Average wind speed during the last 24 hours: 6 mph
Maximum wind gust in the last 24 hours: 13 mph
New snowfall in the last 24 hours: 1-2 inches
Total snow depth: 82 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Spokane NWS
For 2000 ft. to 4000 ft.
Tuesday Tuesday Night Wednesday
Weather: Partly Sunny Mostly Cloudy Chance Rain
Temperatures: 44 deg. F. 31 deg. F. 48 deg. F.
Wind Direction: SW S SE
Wind Speed: 5-7 5-7 8
Expected snowfall: 0 in. 0 in. 0 in.
For 4000 ft. to 6000 ft.
Tuesday Tuesday Night Wednesday
Weather: Mostly Cloudy Mostly Cloudy Chance Rain
Temperatures: 36 deg. F. 29 deg. F. 42 deg. F.
Wind Direction: SW S S
Wind Speed: 7-9 7-9 8
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.