THIS AVALANCHE ADVISORY EXPIRED ON February 6, 2019 @ 6:40 am
Avalanche Advisory published on February 5, 2019 @ 6:40 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

Brrrrrr!  The weekends storms came in warm and left cold which helped them bond well to the crust underneath.  Heads ups for wind slabs in different locations than usual, the winds have been coming out of the north with this cold weather.  The cold also means the snow is very low density, loose dry slides could be a problem that can knock you off your feet in steep terrain.  And we can't forget to mention our buried persistent weak layer

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

Brrrrrr!  The weekends storms came in warm and left cold which helped them bond well to the crust underneath.  Heads ups for wind slabs in different locations than usual, the winds have been coming out of the north with this cold weather.  The cold also means the snow is very low density, loose dry slides could be a problem that can knock you off your feet in steep terrain.  And we can't forget to mention our buried persistent weak layer

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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The cold artic air means that we have transport winds coming from the north, but they have been switching directions as we are right on the edge of the cold weather area.  Heads up out there for wind slabs developing on the ridges and open areas.  Look for chalky, pillow like, hollow sounding snow.  Expect wind slabs to continue to form due to cold weather and low snow density, it will take the new snow longer to settle and bond together so it is still avaliable for transport.

Avalanche Problem 2: Persistent Slab
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Fortunately the warm weather on Friday and Saturday destroyed the crop of surface hoar that had formed last week. Unfortunately still down there is the buried layer from January.  Check for it in shaded and sheltered northern aspects such as big open timber and sheltered draws.  Dig down to assess and don't let it catch you by surprise. 

Avalanche Problem 3: Loose Dry
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Cold smoke blower powder, the likes of which we really haven't had yet this winter!  The low density of this snow and the cold temperatures mean the new snow isn't consolidating fast into slabs.  Sloughing is easy in steep terrain over 40o. This loose snow can surprise a rider and is enough to take someone for a ride into a tree or over a cliff if they aren't careful.  Luckily for us, this snow is very fun to ride or slide in on more conservative terrain.

recent observations

Not of concern today, but might be soon as these cold temperatures hang around at least into the weekend is near surface faceting in the snowpack.  The warm, wet weather on Friday and Saturday froze into solid crusts that are now buried under 6" to 8" of light, fluffy, cold powder.  This crust layer is enough of a barrier in the snowpack to hamper temperature movement so we might see some faceting associated with this crust layer.  We'll find out Thursday!  

Once again, thank you everyone for observations, especially Silver Mountain for their help with Tuesday's forecast.  

Weather and CURRENT CONDITIONS
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 Chance Snow Showers Mostly Sunny
Temperatures: 22 deg. F. 12 deg. F. 19 deg. F.
Wind Direction: NE N NE
Wind Speed: 10-15 5-8 NE
Expected snowfall: <1" in. <0.5" in. 0 in.
For 4000 ft. to 6000 ft.
Tuesday Tuesday Night Wednesday
Weather: Snow Showers LIkely Chance Snow Showers Slight Chance Snow Showers
Temperatures: 13 deg. F. 6 deg. F. 10 deg. F.
Wind Direction: S E NE
Wind Speed: 5-9 5-8 6-8
Expected snowfall: 1" in. 1-2 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.