THIS AVALANCHE ADVISORY EXPIRED ON February 8, 2020 @ 6:40 am
Avalanche Advisory published on February 7, 2020 @ 6:40 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

Expect to find lingering storm slabs and wind slabs from the first round of storms that hit us Wednesday - Thursday night. Avalanche danger will increase by Saturday morning as we get hit by another 6 to 10 inches Friday night. Expect to find sensitive storm slabs and wind slabs on Saturday. 

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

Expect to find lingering storm slabs and wind slabs from the first round of storms that hit us Wednesday - Thursday night. Avalanche danger will increase by Saturday morning as we get hit by another 6 to 10 inches Friday night. Expect to find sensitive storm slabs and wind slabs on Saturday. 

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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There have been winds from multiple directions in the past 24 to 48 hours, so expect to find small wind slabs on all aspects at our ridges. This danger will ramp up on Saturday as more snow is avalaible for transport accompanied by strong winds on Friday night. Look for chalky, pillowy snow that is hollow sounding.  If you see cracking when you are traveling on the ridges, this is an indicator you have hit sensitive wind slabs and should avoid those starting zones.

Avalanche Problem 2: Storm Slab
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Expect to find small storm slabs from the couple of new inches of snow we recieved overnight. This problem will ramp up for Saturday  if we recieve the predicted 6 to 10" tonight.  Up high this will be dry storm slabs, but could transition to wet slabs at our lower elevations.  Yesterday, the snow was wet enough around 4000 - 4800 for us to see rollerballs.  

advisory discussion

The deadline for the Doug Abromeit Avalanche Scholarship is coming up on February 28th.  If you're 14-24 years old you could win your spot in a level 1 avalanche class next year for free.  Go to our education page for details.

recent observations
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Yesterday we traveled to the Dominion Peak area and found between 12 and 14 inches (30-38cm) of snow up high. This was showing good bonding to the ice crust where we were looking, but I don't trust that across the whole advisory area.  Give that a thorough assessment in the areas you are traveling.  We had storm slabs that were stubborn and observed wind slabs in their usual locations. I expect the storm slabs to be more sensitive on Saturday as more snow stacks up.  

My main concern and point of uncertainty right now is a weak layer of snow that is sandwiched between two ice crusts from last weekend's heinous weather. At Dominion, the upper crust was about 5 cm thick and now buried about a foot down.  In some locations it was bridging or supporting the weight of the pack above it.  In other locations it was collapsing and propegating in pit tests.  When more weight comes in on Saturday, this might become a bigger problem.  Assess this in your area and use caution before stepping out into bigger terrain. Sunday and Monday we also found widespread surface hoar. Much of this got knocked down by sunshine and winds later in the week, but I expect there are lingering pockets in sheltered, shaded areas.  With new snow on top, this will become reactive.  

What I'm trying to say is that there are a couple of near surface problems that weren't much of a problem yesterday and going into Friday. These could become bigger problems going into Saturday as we get more loading on top. Use your avalanche common sense and test your area before stepping out into bigger terrain.  

 

Weather and CURRENT CONDITIONS
Two-Day Mountain Weather Forecast Produced in partnership with the Spokane NWS
For 2000 ft. to 4000 ft.
Friday Friday Night Saturday
Weather: Chance snow then chance rain/snow rain then rain/snow snow showers
Temperatures: 36 deg. F. 35 deg. F. 36 deg. F.
Wind Direction: SW SW SW
Wind Speed: light 9-15 8-13
Expected snowfall: <.5 in. <1 in. 1-2 in.
For 4000 ft. to 6000 ft.
Friday Friday Night Saturday
Weather: Snow Heavy Snow and very windy Heavy snow and windy
Temperatures: 30 deg. F. 22 deg. F. 26 deg. F.
Wind Direction: W SW W
Wind Speed: 9-17 31-36, G49 24-29
Expected snowfall: 1-3 in. 6-10 in. 3-5 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.