THIS AVALANCHE ADVISORY EXPIRED ON February 21, 2018 @ 6:57 am
Avalanche Advisory published on February 20, 2018 @ 6:57 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

The storm slabs and wind slabs from the President's Weekend storms are still working on stabilizing after such a big and rapid load.  Most areas are resting on a layer of weak facets and the slick rain crust sliding surface. When headed into the backcountry, use careful snowpack evaluation, cautious route-finding and conservative decision making. 

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

The storm slabs and wind slabs from the President's Weekend storms are still working on stabilizing after such a big and rapid load.  Most areas are resting on a layer of weak facets and the slick rain crust sliding surface. When headed into the backcountry, use careful snowpack evaluation, cautious route-finding and conservative decision making. 

3. Considerable

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

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.
    Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Wind Slab
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Strong winds accompanied the cold front that came through after the storm and transported the loose available snow to create sensitive wind slabs.  Because of the direction of the winds associated with a cold front in our area, these wind slabs are primarily on the opposite side of where we usually expect our wind loading.  

Avalanche Problem 2: Storm Slab
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Heavy loading across the region from Friday - Sunday has formed sensitive storm slabs at all elevation bands.  The storm slabs are resting on a layer of weak facets with a thick rain crust that has led to sensitive avalanche conditions on all aspects and elevations above 4000' in the open areas. 

recent observations

Red flags were prevalent in the backcountry yesterday.  Widespread whoomphing that I could feel when I travelled over areas, as well as being able to feel collapsing from a partner travelling behind me over areas that I didn't trigger first.  We also observed shooting cracks as we were travelling and areas of recent avalanche activity.  The storm slabs are sensitive in pit tests and unfortunately the colder temperatures will likely slow down the stabilizing process. 

If you have any recent observations, we'd love to hear them. Feel free to email me at mrhendrickson@fs.fed.us.

Weather and CURRENT CONDITIONS
Weather observations from the Region
0600 temperature: -5 deg. F.
Max. temperature in the last 24 hours: 0 deg. F.
Average wind direction during the last 24 hours: N
Average wind speed during the last 24 hours: 3 mph
Maximum wind gust in the last 24 hours: 5 mph
New snowfall in the last 24 hours: 2 inches
Total snow depth: 79 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 Decreasing Clouds Increasing Clouds
Temperatures: 15 deg. F. 5 deg. F. 21 deg. F.
Wind Direction: E NE E
Wind Speed: light 6 light
Expected snowfall: 0 in. 0 in. 0 in.
For 4000 ft. to 6000 ft.
Tuesday Tuesday Night Wednesday
Weather: Mostly Cloudy Mostly Cloudy Mostly Cloudy
Temperatures: 12 deg. F. 5 deg. F. 14 deg. F.
Wind Direction: W SW W
Wind Speed: 3-5 5 5-7
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.