THIS AVALANCHE ADVISORY EXPIRED ON January 10, 2018 @ 6:41 am
Avalanche Advisory published on January 9, 2018 @ 6:41 am
Issued by Jeff Thompson - Idaho Panhandle Avalanche Center

Selkirks/Cabinets
St. Regis Basin/Silver Valley

bottom line

Most of the forecast region received rain over the past couple days.  The rain in most areas has frozen into a firm crust on or near the surface.  Once that crust gets more snow on it, it could be problematic. Rain crusts can make nice sliding surfaces. Let's hope the next storm comes in wet and turns dry. Wet snow will have a much better chance of sticking to that rain crust then a dry slab would. 

How to read the advisory

Selkirks/Cabinets
St. Regis Basin/Silver Valley

How to read the advisory

Most of the forecast region received rain over the past couple days.  The rain in most areas has frozen into a firm crust on or near the surface.  Once that crust gets more snow on it, it could be problematic. Rain crusts can make nice sliding surfaces. Let's hope the next storm comes in wet and turns dry. Wet snow will have a much better chance of sticking to that rain crust then a dry slab would. 

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.

2. Moderate

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Below Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
    Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Persistent Slab
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The persistent layer I'm most concerned with is buried surface hoar.  The buried surface hoar isn't in all areas but is pretty reactive in the places it got buried.  The most likely places to find buried surface hoar will be wind and sun sheltered aspects and elevations.  Yesterday, we found the buried surface hoar alive and well at 6300' on a WSW face. It was buried about 12'' under the surface.

Avalanche Problem 2: Deep Slab
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The November crust is still lurking at the bottom of the snowpack. It hasn't proven to be to reactive but is still something to consider. The more snow we get, the more that layer will be isolated and hopefully become a nonfactor.

Avalanche Problem 3: Storm Slab
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The upper elevations of the Selkirks and Cabinet mountains received up to 10'' of snow 2 nights ago.  The snow fell on an ice crust.  The interface between that firm crust and the soft snow is something to watch. Right now that new snow is such a soft slab that there really isn't any energy in that interface....just good skiing!

advisory discussion

Thursday- 3-5'' above 4,000'

Weather and CURRENT CONDITIONS
Weather observations from the Region
0600 temperature: 35 deg. F.
Max. temperature in the last 24 hours: 37 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 8-10 mph
Maximum wind gust in the last 24 hours: 16 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 100 cm inches
Two-Day Mountain Weather Forecast Produced in partnership with the Spokane NWS
For 2000 ft. to 4000 ft.
Tuesday Tuesday Night Wednesday
Weather: Rain Rain Rain
Temperatures: 38 deg. F. 31 deg. F. 34 deg. F.
Wind Direction: SW SW SW
Wind Speed: 5-8 6-9 6-9
Expected snowfall: 0 in. 0 in. 0 in.
For 4000 ft. to 6000 ft.
Tuesday Tuesday Night Wednesday
Weather: Rain / Snow Snow Snow
Temperatures: 35 deg. F. 23 deg. F. 28 deg. F.
Wind Direction: SW SW SW
Wind Speed: 11-13 13-15 12-14
Expected snowfall: 1'' in. 1'' in. 1'' 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.