THIS AVALANCHE ADVISORY EXPIRED ON February 26, 2020 @ 6:44 am
Avalanche Advisory published on February 25, 2020 @ 6:44 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

With over a foot of snowfall at the highest elevations between Sunday and Monday, expect to find sensitive wind slabs on the leeward slopes.  Watch for storm slabs and make sure to check your locations to see what the interface between the new and old snow is. Weather is calm for the next couple of days, so it should help the snowpack stabilize. 

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

With over a foot of snowfall at the highest elevations between Sunday and Monday, expect to find sensitive wind slabs on the leeward slopes.  Watch for storm slabs and make sure to check your locations to see what the interface between the new and old snow is. Weather is calm for the next couple of days, so it should help the snowpack stabilize. 

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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We recieved a shot of new snow, with over a foot in some advisory locations with very strong winds. Watch for sensitive wind slabs and cross loading on the leeward slopes. When the winds move the snow around it can stack up these wind slabs to several feet deep.  Look for where snow is blowing across the ridges and watch out for rounded, textured pillows. Shooting cracks are a red flag for wind slabs. 

Avalanche Problem 2: Storm Slab
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The new snow fell on a variety of surfaces. On the south sides, there is a nice smooth sun crust buried down there.  Some places may have lingering surface hoar. Dig a pit at your location and check to see how bonding between the new snow and the old snow interface is. With no new snow predicted for the next several days, I expect this danger to decrease.  

Avalanche Problem 3: Persistent Slab
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With last weeks clear and cold weather we saw lots of surface hoar growth. The sun took care of most of it on the southern side, and Sunday's strong winds knocked it down at our above treeline locations.  I expect to find pockets of buried surface hoar under the most recent storm in shaded and sheltered areas. There is another patchy layer of surface hoar that was buried during the previous storm as well that is now much deeper.  This is a type of problem that I automatically assume is guilty when I'm headed out. Check that interface between the new storm and the last for this culprit. 

advisory discussion

This is the last week to get your submissions in for the Doug Abromeit Avalanche Scholarship. See details on the education tab.  

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: Partly Sunny Slight Chance Snow Slight Chance Rain/Snow then slight chance rain
Temperatures: 38 deg. F. 29 deg. F. 41 deg. F.
Wind Direction: Calm Calm SW
Wind Speed: Calm Calm 3-5
Expected snowfall: 0 in. 0 in. 0 in.
For 4000 ft. to 6000 ft.
Tuesday Tuesday Night Wednesday
Weather: Partly Sunny Slight Chance Snow Chance Snow
Temperatures: 26 deg. F. 22 deg. F. 28 deg. F.
Wind Direction: SW SW W
Wind Speed: 6-8 9 9
Expected snowfall: 0 in. 0 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.