THIS AVALANCHE ADVISORY EXPIRED ON January 25, 2020 @ 6:24 am
Avalanche Advisory published on January 24, 2020 @ 6:24 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

A warm storm hitting our area will continue to add heavy, dense snow to our higher elevations (above ~5500ft) and rain below.  Expect to see small loose wet slides at the lower and middle elevations. At the upper elevations expect to see dense storm slabs that are forming over the weaker lighter snow from last weekend.  

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

A warm storm hitting our area will continue to add heavy, dense snow to our higher elevations (above ~5500ft) and rain below.  Expect to see small loose wet slides at the lower and middle elevations. At the upper elevations expect to see dense storm slabs that are forming over the weaker lighter snow from last weekend.  

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: Storm Slab
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With above freezing temperatures up to 6000 ft last night, the snow that fell is heavy and dense.  This snow has fallen on a variety of surfaces on the different aspects. On the north sheltered aspects, there are isolated patches of surface hoar that are now buried.  On the south aspects, there is a sun crust underneath the new storm snow.  It came in colder yesterday, so it may have poor bonding at the higher elevations.  As you are traveling, make sure to check out how this snow has bonded to the layers underneath where you are. I would be especially cautious around slopes that are above 35 degrees and convex roll overs where the snow might be thinner.  

Avalanche Problem 2: Loose Wet
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With temperatures that didn't drop below freezing and precipitation that came in as rain, expect this danger to be present until the snowpack has a chance to lock back up by freezing.  Expect to see lots of rollerballs and point wet slides as you are traveling below 5500 ft.  While these are less hazardous than a storm slab, they can take an unaware person for a ride in steep terrain.  

Avalanche Problem 3: Wind Slab
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The winds are predicted to be steady with gusts up in the upper 30s at the higher ridgetops. As snow falls above 5500ft today, expect wind slabs to form.  

recent observations
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Mullan Pass, our hightest weather observation station at 6001 ft recorded a low of 34 last night. All the other stations remained above freezing as well. Both the Sunset and Lookout Snotels recieved 0.2 inches of SWE last night, but no new inches of snow.  The good news is that this isn't as much SWE/rain as we were expecting.The rain swath didn't hit the forecast area as hard as it hit town.  SWE stands for snow water equivalent and is the amount of water contained within the snowpack if you were to melt it down. 

Leading up to this storm, we had some nice sunny days that helped stabilize our snowpack.  They also helped form a sun crust on our southern aspects.  The clear nights saw surface hoar growth in the shaded northern aspects.  This means that we have a complicated surface under this new layer of snow. These areas are my main concern as we go into the weekend to see how reactive they are as we get more weight on them.  If you are out and about and observe these layers, please send in an observation, the more data across the forecast area the better!  Have a safe weekend and try to stay dry as you travel through the lower elevations.

A congratulations go out to our Friends of IPAC board member Gabe and his wife for bringing a new backcountry traveler into this world. I'll be expecting observations from him soon!

 

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: Rain Showers likely then slight chance rain/snow chance rain/snow
Temperatures: 39 deg. F. 34 deg. F. 37 deg. F.
Wind Direction: SW SW variable
Wind Speed: 6-9 5-7 light
Expected snowfall: 0 in. 0 in. 0 in.
For 4000 ft. to 6000 ft.
Friday Friday Night Saturday
Weather: Snow and windy Breezy. Snow Showers then chance snow showers chance snow
Temperatures: 33 and falling deg. F. 29 deg. F. 30 deg. F.
Wind Direction: SW SW S
Wind Speed: 17-25, G38 17-22 14-16
Expected snowfall: 1-3 in. 1-3 in. 1 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.