Despite recent benign weather our snowpack structure remains weak with human triggered slides possible resulting in large and destructive avalanches. The best holiday gift to a friend and loved one is careful evaluation of snow structure and terrain while dealing with this complex Persistent Slab problem.
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Above 6500 ft.
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5000-6500 ft.
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3500-5000 ft.
Observations from around the area confirm that our persistent slab problem has not gone away. Last weeks bountiful storm formed 2 to 4 foot slabs on several inches of weak sugary snow at all elevations and aspects. As time elapses these slabs are becoming less reactive to human triggering but snowpit tests reveal that human triggered slides are still possible with resulting slides large and destructive. Therefore careful snowpack evaluation, cautious route finding and conservative decision making are essential. With a relatively thin snowpack it takes just a few minutes of digging to reveal this weak snow structure firsthand. When in doubt, terrain management is the easiest and safest way to answer this complex problem.
With sunshine, powder conditions and the holiday season upon us it is easy to get a bit complacent. Our snowpack is not exhibiting the warning signs of instability that it announced last week such as shooting cracks (photo 1 photo 2) and collapsing (photo). Digging into the snowpack paints a different picture with a 2 to 4 foot slab of snow on several inches of weak sugary snow in many locations. The slab is settling out and gaining a bit of strength but the weak snow remains weak. Stability test results show propagation within the slab confirming that a human triggered slide is possible with resulting slides being large and destructive. Given the serious consequences of triggering a Persistent Slab, carefully evaluate the snow structure and terrain.
Join us at Stumptown Snowboards in Whitefish on January 3 at 7:00 pm for a free, engaging, and entertaining 1 hour avalanche awareness presentation. Details here.
A storm passing to the south of us may produce a few flurries but otherwise expect a cold dry Christmas. Currently, northeasterly winds are light with partly cloudy skies and no new snow in the past 24 hours. Tomorrow will be dry with temperatures a few degrees warmer than today. Active weather returns mid-week lasting into the weekend.
| Monday | Monday Night | Tuesday | |
|---|---|---|---|
| Cloud Cover: | Mostly cloudy and cold. | Mostly cloudy and cold. | Mostly cloudy and cold. |
| Temperatures: | 5 to 10 deg. F. | -10 to 5 deg. F. | 8 to 13 deg. F. |
| Wind Direction: | Northeast | Southeast | Southwest |
| Wind Speed: | 0 to 10 mph | 0 to 10 mph | 0 to 10 mph |
| Snowfall: | 0 in. | 0 in. | 0 in. |
| Snow Line: |
This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires at midnight on the posted day unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.
