THIS AVALANCHE ADVISORY EXPIRED ON February 2, 2018 @ 4:53 pm
Avalanche Advisory published on February 1, 2018 @ 4:53 pm
Issued by Kevin Davis - Idaho Panhandle Avalanche Center

Selkirks/Cabinets

bottom line

In that past 5-7 days we have received steady snowfall, witnessed above freezing temperatures, and endured some rain.  This has created new surface layers and also helped to stabilize some problem layers last week.  Eric revealed two ice crusts in the upper 18 inches that could present problems with enough new snow or windloaded snow.  Normal caution is advised up high but use caution.   Problem weak layers are more likely in northerly aspects on large, steep, exposed and open terrain.

How to read the advisory

Selkirks/Cabinets

How to read the advisory

In that past 5-7 days we have received steady snowfall, witnessed above freezing temperatures, and endured some rain.  This has created new surface layers and also helped to stabilize some problem layers last week.  Eric revealed two ice crusts in the upper 18 inches that could present problems with enough new snow or windloaded snow.  Normal caution is advised up high but use caution.   Problem weak layers are more likely in northerly aspects on large, steep, exposed and open terrain.

2. Moderate

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Above Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

1. Low

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Near Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

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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The wind will be moderate out of the SW for the next couple days and with light new snowfall epected each day this will be enough to load up aspects.  The crusts underneath will allow new snow a better sliding surface to get snow moving and possibly slab up.  Storm slabs that form from changes in density, crystal type, or temp may occur but it seems like the weather will be persistently cold and SW wind more consistent.  This is why the wind is the more concerning factor for this advisory.  Thank to Schweitzer Mountain Resort for hosting this advisory.

Avalanche Problem 2: Persistent Slab
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You remember the fun from last week.  Alot of natural and human triggered avalanches were witenessed throughout our forecast region.  With a better than average snowpack now, we have enough wieght loaded up over 3 persistent weak layers, January 3 hoar, MLK crust, and Tday crust.  It is unlikely that you will trigger these, but we did see that they still can be awakened.  The best way to tease the grizzly bear is to trigger a smaller slide in steep terrain that triggers one of the deeper layers or, play on big, steep, exposed slopes that have more variability in snow depth where you would more easily stress those deeper layers.  Remember, February is an active month for human triggered avalanches in our forecast area.

recent observations

Things have settled down from the active period we had last week.  No new observations of avalanche activity this week.  Look at our Friends Facebook page if you're interested in the avalanche activity from last week.  Jeff and Tom Eddy took some good pictures of the deep slab avalanche that was triggered explosivley in the north bowl last Thursday.  Also, Tom keeps a frequent and comprehensive record of the weather and snowpack that is excellent for tracking conditions.  Thanks Tom!

 

Weather and CURRENT CONDITIONS
weather summary

Today and tonight...Light to moderate precipitation will continue across the eastern portion of the forecast area this morning as a moisture laden warm front gets pushed out of the region by a weak, but fast moving upper level cold front. That cold front should be east of the area around 15z this morning and will result in drying from the west. Northwest flow will keep a good chance for up-sloping precipitation for the Cascades, the northern mountains and the Panhandle mountains through the morning and into
early afternoon.

Weather observations from the Region
0600 temperature: 26 deg. F.
Max. temperature in the last 24 hours: 26 deg. F.
Average wind direction during the last 24 hours: WSW
Average wind speed during the last 24 hours: 18 mph
Maximum wind gust in the last 24 hours: 47 @ 5am mph
New snowfall in the last 24 hours: 1" inches
Total snow depth: 110 snotel inches
Two-Day Mountain Weather Forecast Produced in partnership with the Spokane NWS
For 2000 ft. to 4000 ft.
Thursday Thursday Night Friday
Weather: A chance of snow before 10am, then rain and snow. High near 36. Southwest wind 9 to 11 mph. Chance of precipitation is 90%. Total daytime snow accumulation of less than a half inch possible. A chance of rain and snow before 2am, then a chance of snow. Mostly cloudy, with a low around 34. Southwest wind 3 to 7 mph. Chance of precipitation is 40%. New snow accumulation of less than a half inch possible. A chance of snow before 8am, then a chance of rain and snow between 8am and 10am, then a chance of rain after 10am. Cloudy, with a high near 38. Southwest wind around 8 mph. Chance of precipitation is 30%. New snow accumulation of less than a half inch possible.
Temperatures: 36 deg. F. 34 deg. F. 38 deg. F.
Wind Direction: SW SW SW
Wind Speed: 9-11mph 3-7mph 8mph
Expected snowfall: <1/2" in. <1/2" in. <1/2" in.
For 4000 ft. to 6000 ft.
Thursday Thursday Night Friday
Weather: Snow, mainly after 10am. High near 32. Breezy, with a west wind 16 to 22 mph, with gusts as high as 36 mph. Chance of precipitation is 100%. Total daytime snow accumulation of 1 to 3 inches possible. Snow likely, mainly after 4am. Cloudy, with a low around 27. Southwest wind 13 to 15 mph. Chance of precipitation is 60%. New snow accumulation of less than one inch possible. Snow likely, mainly before 10am. Cloudy, with a steady temperature around 27. West wind 14 to 16 mph, with gusts as high as 24 mph. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible.
Temperatures: 32 deg. F. 27 deg. F. 27 deg. F.
Wind Direction: W SW W
Wind Speed: 16-22mph, gusts 36 13-15mph 14-16mph, gusts 24
Expected snowfall: 1-3 in. <1" in. <1/2" 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, a rescue beacon and a well-equipped first aid kit.  For a recorded version of the Avalanche Advisory call (208)765-7323 and view the Friends of the Panhandle Avalanche Center Facebook page.