THIS AVALANCHE ADVISORY EXPIRED ON February 20, 2019 @ 6:47 am
Avalanche Advisory published on February 19, 2019 @ 6:47 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

The snow from last week has continued to strengthen as it settles but with moderate winds from multiple directions over the weekend, expect to find wind slabs on all aspects below the ridgelines. Also look for cross loading on steep, open terrain that has been exposed to the winds.  

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

The snow from last week has continued to strengthen as it settles but with moderate winds from multiple directions over the weekend, expect to find wind slabs on all aspects below the ridgelines. Also look for cross loading on steep, open terrain that has been exposed to the winds.  

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: Wind Slab
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Wind slabs are our main concern out in the backcountry right now.  We've had winds from our normal S-SW direction, but they have been battling a cold front that gives us winds from the N.  As a result we have small wind slabs that can be found on all aspects above treeline. Heads up for cross loaded gullies and wide open slopes as well.  Expect more wind slab development over the next couple of days on all aspects as the snow today and tonight comes in from the SW and then the winds switch back to the N again. 

Avalanche Problem 2: Persistent Slab
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We have multiple persistent weak layers buried in the pack right now.  Closest to the surface we are keeping an eye on the cold, lighter snow from two storms ago. This weekend it was becoming less reactive in tests and there temperature gradients across it show it gaining strength.  Next down in the pack is the ice crust with associated rounding facets. Temperature gradients also show this to be gaining strength, but it was still popping in pit tests on Sunday.  Both of these layers are widespread on all aspects.  Buried surface hoar can still be found in isolated locations on the NW-N-NE aspects.   We will continue to keep an eye on these layers.  

recent observations

Thank you Silver Mountain and the National Ski Patrol Level II class for observations this week.  

Touring around the backcountry over the Holiday weekend, we were able to see the snowpack become more stable after coming out of last week's High forecast.  One thing to take into consideration before this next storm is that it got just sunny enough on Saturday to form a sun crust on the Southern aspects, up to our highest elevations.  This could potentially provide a smooth sliding surface as more weight gets added on top of it.  

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 then Snow Snow Snow likely
Temperatures: 23 deg. F. 20 deg. F. 28 deg. F.
Wind Direction: variable S Variable
Wind Speed: 5 5 light
Expected snowfall: 1-3 in. 3-7 in. <1 in.
For 4000 ft. to 6000 ft.
Tuesday Tuesday Night Wednesday
Weather: Chance snow then snow Snow Snow
Temperatures: 16 deg. F. 14 deg. F. 21 deg. F.
Wind Direction: SW SW NE
Wind Speed: 11-17 10-17 6-9
Expected snowfall: 1-3 in. 3-5 in. 1-3 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.