THIS AVALANCHE ADVISORY EXPIRED ON January 24, 2018 @ 6:56 am
Avalanche Advisory published on January 23, 2018 @ 6:56 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

Snowpack conditions are variable across the advisory region.  Heightened avalanche conditions exist on specific terrain features and require careful evaluation.  Observations of instabilities around the region include: buried surface hoar, windslabs, buried ice crusts with facets, and in some locations still the deep persistent weak layer. Slope specific evaluation is needed before skiing or riding. 

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

Snowpack conditions are variable across the advisory region.  Heightened avalanche conditions exist on specific terrain features and require careful evaluation.  Observations of instabilities around the region include: buried surface hoar, windslabs, buried ice crusts with facets, and in some locations still the deep persistent weak layer. Slope specific evaluation is needed before skiing or riding. 

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: Persistent Slab
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The variable precipitation pattern we have seen in the last couple of weeks has left near surface crusts and associated weak snow in most areas of the region.  These crusts vary in thickness, depth, and strength, so it is essential to dig into the snow, test the reactivity of the weak layers, and make a slope specific evaluation.  The new snow loads coming in will increase the tension on these weak layers

Avalanche Problem 2: Wind Slab
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Ridgetop winds have been variable in direction, leaving lingering windslabs. Expect to see new windslabs being formed as transport winds accompany the storm coming in.  

Avalanche Problem 3: Storm Slab
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Expect the avalanche danger to increase as more snow hits the region later today and tonight.

recent observations

Our fluctuating precipitation patterns have created variable snowpack stability and riding conditions across the region.  It is important that you assess the area you choose to ride by digging down into the snowpack and getting the picture at your location.  If you aren't comfortable doing that, it is a great year to take an avalanche class. Check our website for details on upcoming classes, including the IPAC class at the end of the month with field days being held at Lookout Pass.  

Thank you to Panhandle Backcountry staff members Larry and Mike (here) and Silver Mountain Ski Patrollers Miles, Brian, and Ty (here) for observations this week.  Observations from different locations in the region are very appreciated!

Weather and CURRENT CONDITIONS
Weather observations from the Region
0600 temperature: 28 deg. F.
Max. temperature in the last 24 hours: 32 deg. F.
Average wind direction during the last 24 hours: WNW
Average wind speed during the last 24 hours: 3-6 mph
Maximum wind gust in the last 24 hours: 17 mph
New snowfall in the last 24 hours: 6 inches
Total snow depth: 56 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Spokane NWS
For 2000 ft. to 4000 ft.
Tuesday Tuesday Night Wednesday
Weather: Chance snow then snow Heavy snow Rain/Snow
Temperatures: 32 deg. F. 31 deg. F. 36 deg. F.
Wind Direction: South South South
Wind Speed: 7 7-10 9
Expected snowfall: 1 in. 4-8 in. 1-2 in.
For 4000 ft. to 6000 ft.
Tuesday Tuesday Night Wednesday
Weather: Chance of snow then snow Heavy snow Snow then snow likely
Temperatures: 26 deg. F. 25 deg. F. 31 deg. F.
Wind Direction: South South South
Wind Speed: 9-14 15-17 15
Expected snowfall: 1 in. 6-10 in. 2-4 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.