THIS AVALANCHE ADVISORY EXPIRED ON December 22, 2018 @ 6:53 am
Avalanche Advisory published on December 21, 2018 @ 6:53 am
Issued by Kevin Davis - Idaho Panhandle Avalanche Center

Selkirks/Cabinets

bottom line

Since December 18th the Selkirks and Cabinets have picked up about 10 inches of new snow.  Last night the mountains received another 3-5 inches of new snow and that was accompanied by strong winds and dropping temperatures.  That will have created some heavy windloading on all easterly aspects as well as north and potentially northwest.  It would be wise to avoid ridgetop loading areas for today and possibly the weekend.

How to read the advisory

Selkirks/Cabinets

How to read the advisory

Since December 18th the Selkirks and Cabinets have picked up about 10 inches of new snow.  Last night the mountains received another 3-5 inches of new snow and that was accompanied by strong winds and dropping temperatures.  That will have created some heavy windloading on all easterly aspects as well as north and potentially northwest.  It would be wise to avoid ridgetop loading areas for today and possibly the weekend.

3. Considerable

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

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.
    Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Wind Slab
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Westerly winds have been blowing with all the new snow we have received this week so windloaded areas are piled up deeper than the surrounding terrain.  Winds were strong with the new snow last night so expect that windslabs will be touchy today.  Colder weather will allow weakness in the windslabs to persist longer into the weekend so keep your guard up in windloaded ridgetop areas.  

Avalanche Problem 2: Persistent Slab
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We're looking at about 5-6 feet of snow in the mountains above 5,000 feet.  Rain up to 5,000 feet has created some crusts and helped the bonding in weak layers.  Recall the weak layers that we have been talking about when you venture into higher terrain or terrain that is more exposed.  The surface hoar weak layer about mid-pack is gaining strength but has not gone away.  Weak facets at the base may still exist especially in areas with shallower snow.  Be cautious on and around steep slopes above 5,000 feet because of the possibility of triggering these two weak layers.  They will settle out in time with more snow load. 

recent observations

Rain to about 5,000 feet earlier this week has created a breakable crust that is now buried by the new snow.  It is probably not thick enough to form a sliding surface.  Rain yesterday has potentially formed another crust that will be most noticeable below 5,000 feet and will be partially buried as well.  Above 5,000 feet expect firmer snow and windloading.  No avalanches were reported with the storm yesterday but clearing weather may allow you to see if there is any recent avalanche activity.

Weather and CURRENT CONDITIONS
weather summary
Partly cloudy today with decreasing temperatures and continued SW winds.  This could create some icy conditions below 5,000 feet and firming snow above 5,000 feet.

 
Weather observations from the Region
0600 temperature: 20F deg. F.
Max. temperature in the last 24 hours: 32F deg. F.
Average wind direction during the last 24 hours: W
Average wind speed during the last 24 hours: 10 mph
Maximum wind gust in the last 24 hours: mph
New snowfall in the last 24 hours: 5 inches
Total snow depth: 53 inches
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.