THIS AVALANCHE ADVISORY EXPIRED ON February 21, 2018 @ 6:53 am
Avalanche Advisory published on February 20, 2018 @ 6:53 am
Issued by Jeff Thompson - Idaho Panhandle Avalanche Center

Selkirks/Cabinets

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After a week of good snow and strong winds we'll be hanging out in a cold high pressure for the next 24 hours. There was a lot of reverse loading above treeline and near ridges. Areas that are normally thought of as leeward slopes may have newly formed wind slabs on them.  We're getting initial information about a snowmobile triggered avalanche in Echo bowl yesterday. No details yet... Stay safe out there!

How to read the advisory

Selkirks/Cabinets

How to read the advisory

After a week of good snow and strong winds we'll be hanging out in a cold high pressure for the next 24 hours. There was a lot of reverse loading above treeline and near ridges. Areas that are normally thought of as leeward slopes may have newly formed wind slabs on them.  We're getting initial information about a snowmobile triggered avalanche in Echo bowl yesterday. No details yet... Stay safe out there!

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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Expect wind slab formation on all aspects near ridge lines. The prevailing winds for the Selkirks and Cabinets is out of the W-SW but this storm produced strong sustained winds from the N-NE. Usually when you have wind slabs on top of wind slabs that produces a good slide surface. Triggering a slab avalanche in wind effected ares is the biggest problem in the snowpack right now.  Be especially carful approaching slopes from the bottom.

Avalanche Problem 2: Storm Slab
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Even though wind effected snow is the bigger problem, there're still areas in the trees that are not wind effected. With the cold temperatures, the new snow hasn't had a chance to slab up to much yet.  If you're looking for powder conditions...staying in the trees is your best chance! Because the new snow is sitting on a firm crust it can move but probably won't propagate very far yet.  Be careful around terrain traps ( creek bottoms, road cuts, etc.).

Weather and CURRENT CONDITIONS
Weather observations from the Region
0600 temperature: 0 deg. F.
Max. temperature in the last 24 hours: 18 deg. F.
Average wind direction during the last 24 hours: N-NE
Average wind speed during the last 24 hours: 32 mph
Maximum wind gust in the last 24 hours: 78 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 106 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Spokane NWS
For 2000 ft. to 4000 ft.
Tuesday Tuesday Night Wednesday
Weather: Lt snow Mostly clear Sunny
Temperatures: 21 deg. F. 7 deg. F. 25 deg. F.
Wind Direction: NE NE NE
Wind Speed: 5-7 5-7 5-7
Expected snowfall: 0 in. 0 in. 0 in.
For 4000 ft. to 6000 ft.
Tuesday Tuesday Night Wednesday
Weather: Lt snow Mostly clear Sun / Increasing clouds
Temperatures: -4 deg. F. 0 deg. F. 15 deg. F.
Wind Direction: NE N SW
Wind Speed: 8-10 9-11 7-9
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.