THIS AVALANCHE ADVISORY EXPIRED ON January 23, 2019 @ 6:36 am
Avalanche Advisory published on January 22, 2019 @ 6:36 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

Soft storm slabs are resting on slippery crust and buried surface hoar layer in many locations. Storms coming in later today will add more weight to these slabs at all elevations.  Avalanche danger is going to rise Wednesday with the predicted amounts of snowfall and strong winds hitting the region.  Winter Storm Warning tonight! Play it safe and dial it back.  

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

Soft storm slabs are resting on slippery crust and buried surface hoar layer in many locations. Storms coming in later today will add more weight to these slabs at all elevations.  Avalanche danger is going to rise Wednesday with the predicted amounts of snowfall and strong winds hitting the region.  Winter Storm Warning tonight! Play it safe and dial it back.  

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: Storm Slab
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The storms over the weekend came through with smaller amounts than were predicted and absent of winds.  They are still resting on a weak layer of surface hoar and crust in many of the mid elevation locations.  Even though these slabs are small, heads up in areas such as terrain traps and cliffs, as they can sweep you off your feet in the blink of an eye.  Expect this danger to increase by Wednesday morning as another storm hits the area Tuesday night with totals of up to 20" possible in a 24 hour period.  

Avalanche Problem 2: Persistent Slab
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Our persistent layers still include surface hoar buried from November and basal facets.  These are getting buried deeper each storm and the likelihood of triggering is very low....but with catastrophic consequences.  They will continue to strengthen with time but could be a problem in areas with a thinner snowpack or in steep, convex terrain.  We'd love to hear your reports of where you are finding these!

recent observations

There have been no observations of avalanche activity in the recent past in the forecast area.  Yesterday, it was possible to trigger soft slabs in steep areas where the crust is still present.  From travelling around the forecast area, this crust is predominant up to around 5900 ft.  Above this, the new storms are bonding well with the old storms.  The weekend's storm came in without winds, so there has been minimal recent wind slab development and the old ones have had time to stabilize.  Expect this to change rapidly tonight and tomorrow as as we get a big loading of snow with gusty winds.  Wednesday is going to have several red flags: lots of new snow and lots of wind.  Dial back you objectives for Wednesday and Thursday.  Stay safe this mid-week and enjoy the snow again.  

If you are in Sandpoint on Wednesday night, join the IPAC forecasters for the second Snow Pit Chat of the season.  Matchwood Brewing Company from 6 to 8pm!  See you there.  

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 Heavy Snow then Rain/Snow Rain/Snow
Temperatures: 31 deg. F. 30 deg. F. 35 deg. F.
Wind Direction: SW S W
Wind Speed: 6-9 7-11, G24 5-13, G30
Expected snowfall: 1-2 in. 4-8 in. 1-2 in.
For 4000 ft. to 6000 ft.
Tuesday Tuesday Night Wednesday
Weather: Windy. Chance Snow then Snow Heavy Snow and Windy Heavy Snow and Windy
Temperatures: 22 deg. F. 22 deg. F. 29 deg. F.
Wind Direction: SW SW W
Wind Speed: 17-26 22-25, G44 20-30, G41
Expected snowfall: 1-3 in. 6-10 in. 4-8 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.