THIS AVALANCHE ADVISORY EXPIRED ON January 31, 2018 @ 6:58 am
Avalanche Advisory published on January 30, 2018 @ 6:58 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

Our snowpack continues to gain strength from the past weekend storms, but strong winds came in overnight with new snowfall leading to windslab development.  Todays weather will continue to lend to windslab development. Expect to find windslabs on the northeasterly aspects as well as storm slabs on all aspects above 5000'. Buried weak layers of variable distribution also warrant conservative terrain selection.  Assess the snowpack in each place you plan to ride or slide

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

Our snowpack continues to gain strength from the past weekend storms, but strong winds came in overnight with new snowfall leading to windslab development.  Todays weather will continue to lend to windslab development. Expect to find windslabs on the northeasterly aspects as well as storm slabs on all aspects above 5000'. Buried weak layers of variable distribution also warrant conservative terrain selection.  Assess the snowpack in each place you plan to ride or slide

3. Considerable

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

3. Considerable

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

2. Moderate

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Below Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
    Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Wind Slab
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Strong winds through the night and predicted during the day today will continue to develop windslabs on leeward slopes. Look for rounded pillows of snow near ridgelines, in open trees below ridgelines, and on cross loaded slopes.  Watch for red flags of instability such as whoomphing and cracking.  Avoid wind loaded slopes. 

Avalanche Problem 2: Storm Slab
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The deep snow that we were blessed with over the weekend came in with variable densities and temperatures, and then topped with a layer of rain. The new snow last night and throughout today will add another layer of storm snow.  As temperatures drop from yesterday, the avalanche danger should decrease. 

Avalanche Problem 3: Persistent Slab
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The buried persistent slabs vary spatially throughout the region. It is important to assess the snowpack on each slope you are considering by digging down and checking out the layers.  You can avoid this problem by choosing lower angle terrain.  

recent observations

Observations from Sunday at FAA area, Willow Ridge, and Silver Mountain all showed the storm slabs to be touchy.  Yesterday's warm weather offered the snowpack a chance to settle, but pit results from the afternoon at Silver Mountain were still in the moderate range, showing the storm slabs to still be sensitive. 

Weather and CURRENT CONDITIONS
Weather observations from the Region
0600 temperature: 23 deg. F.
Max. temperature in the last 24 hours: 37 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 15 mph
Maximum wind gust in the last 24 hours: 47 mph
New snowfall in the last 24 hours: 1 inches
Total snow depth: 63 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Spokane NWS
For 2000 ft. to 4000 ft.
Tuesday Tuesday Night Wednesday
Weather: snow likely snow likely then slight chance snow chance snow
Temperatures: 35 deg. F. 25 deg. F. 31 deg. F.
Wind Direction: Southwest Southwest Southwest
Wind Speed: 10-14 10 7-9
Expected snowfall: <1" in. <1 in. 1 in.
For 4000 ft. to 6000 ft.
Tuesday Tuesday Night Wednesday
Weather: Snow showers and windy snow and breezy snow
Temperatures: 25 deg. F. 18 deg. F. 24 deg. F.
Wind Direction: West West West
Wind Speed: 20-25 (G36) 16-21 (G30) 11-14 (G22)
Expected snowfall: 1-3 in. 1-3 in. 1-3 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.