THIS AVALANCHE ADVISORY EXPIRED ON December 25, 2019 @ 6:33 am
Avalanche Advisory published on December 24, 2019 @ 6:33 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

The storm system that rolled through over the weekend wasn't exactly what we were hoping to get for Christmas. Above 6000' we are still seeing reactive basal facets.  Below 6000', the snow pack is still stabilizing after recieving so much moisture.  Temperatures are starting to be more winterlike again, so that should help lock up the lower elevation snowpack.  

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

The storm system that rolled through over the weekend wasn't exactly what we were hoping to get for Christmas. Above 6000' we are still seeing reactive basal facets.  Below 6000', the snow pack is still stabilizing after recieving so much moisture.  Temperatures are starting to be more winterlike again, so that should help lock up the lower elevation snowpack.  

3. Considerable

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Above Treeline
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.

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.
    Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Persistent Slab
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At the higher elevations, there are still buried persistent weak layers. Dense, heavy snow on top of these layers is making the snowpack upside down right now.  When you step out of your skis or off your sled you punch through the snow up to your waist.  This is a sign of instability in the snowpack: it isn't firmer the deeper you get.  This problem will take time to stabilize and fix, so in the mean time it is likely to trigger an avalanche on slopes greater than 30 degrees. When triggered, it is highly likely that these will release all the way to ground.  

Avalanche Problem 2: Wind Slab
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New snow yesterday and last night had the potential to form windslabs on ridges.  These slabs may be small, but if triggered could step down to the deeper buried persistent weak layers and create a much larger avalanche.  

recent observations
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Things are starting to settle from the roller coaster of a storm we experienced over the weekend, but pit results were still reactive yesterday.  In the high elevations, expect settling and collapsing to occur as the snow pack gains strength.  Cooler temperatures will help the lower and mid elevations lock up after the warm up they experienced over the weekend, the rain was a good reset for those areas. The bottom line is that there is potential for human triggered avalanches on steep slopes above 6000 ft. Some spatial variability exists so be prepared to dig a pit and look for red flags everywhere you go. With the low snow levels and avalanche danger, now is not the time to get gnarly.  Manage the current problems by sticking to sheltered, low angle terrain. 

Merry Christmas everyone!

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: Patchy Freezing Fog then Slight Chance Snow Slight Chance Snow then Mostly Cloudy Partly Sunny then Patchy Fog
Temperatures: 33 deg. F. 24 deg. F. 32 deg. F.
Wind Direction: Calm Calm Calm
Wind Speed:
Expected snowfall: 0 in. 0 in. 0 in.
For 4000 ft. to 6000 ft.
Tuesday Tuesday Night Wednesday
Weather: Chance Flurries Chance Flurries Partly Sunny
Temperatures: 24 deg. F. 19 deg. F. 23 deg. F.
Wind Direction: W SW S
Wind Speed: 5-7 8 9
Expected snowfall: 0 in. 0 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.