THIS AVALANCHE ADVISORY EXPIRED ON February 8, 2019 @ 3:43 pm
Avalanche Advisory published on February 7, 2019 @ 3:43 pm
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

NOAA is calling the forecast blustery! In avalanche terms this translates to cold snow and windy conditions. Watch out for wind slabs on all aspects as we've had swirling winds this week with the cold front. The light density snow will be easy to trigger loose slides in our steep terrain. And we are still seeing a buried persistent weak layer down there is isolated areas. 

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

NOAA is calling the forecast blustery! In avalanche terms this translates to cold snow and windy conditions. Watch out for wind slabs on all aspects as we've had swirling winds this week with the cold front. The light density snow will be easy to trigger loose slides in our steep terrain. And we are still seeing a buried persistent weak layer down there is isolated areas. 

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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The cold temperatures have not let this week's snow consolidate. Coupled with more cold, low density snow today, expect wind slab formation to continue over the weekend. The cold temperatures will also make them brittle, so don't expect them to heal up over the weekend. Winds from all directions mean we have to check all aspects for loading zones. Look for chalky, hollow sounding snow.

Avalanche Problem 2: Loose Dry
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Cold unconsolidated snow means it will be easy to trigger point loose slides or sluffs. Don't just write sluffs off: small avalanches kill too. Pay attention to your terrain, loose slides have big consequences where they can push a rider into a terrain trap or over a cliff. Road cuts are a great place to see how easily these are triggered.      

Avalanche Problem 3: Persistent Slab
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We've been talking about this one for a couple weeks now, so it should be no surprise. Heads up in sheltered areas such as draws and big timber below 5900'. In isolated areas we are still getting reactivity in pit tests. The way to be certain is to dig down and test it out. 

recent observations

Join us this weekend for the Silver Mountain Backcountry Weekend. All details can be found here: https://www.silvermt.com/Winter/Events/Backcountry-Weekend

Yesterday we traveled to the Grouse Peaks area. The cold snow was easy to trigger loose slides, but the density made it fun to ride much lower angle terrain! We were seeing wind slabs form while we were there. It doesn't take much to move this light density snow around. While we couldn't find the buried surface hoar yesterday, we did find basal facets reacting around a trigger point. They are still down there, but not one of our top three concerns. Observation for the Tiger Peak area did have a pit with the buried surface hoar reacting. Stay warm this weekend and send observations!

Weather and CURRENT CONDITIONS
weather summary

Winter Weather Advisory

URGENT - WINTER WEATHER MESSAGE
National Weather Service Spokane WA
434 AM PST Fri Feb 8 2019

...PERIODS OF LIGHT SNOW TODAY BECOMING LOCALLY HEAVY TONIGHT
FOLLOWED BY STRONG NORTH WINDS ON SATURDAY...

.Light snow today will become heavier tonight. The heaviest snow
tonight into Saturday will fall over central Washington where 8 to
12 inches will be possible around Wenatchee, Chelan, and Vantage.
Gusty north winds on Saturday will likely create areas of blowing
and drifting snow. Some roads may become impassable due to
drifting snow in central and north central Washington on Saturday.

IDZ003-004-WAZ033-090000-
/O.NEW.KOTX.WW.Y.0010.190208T1234Z-190209T2100Z/
Idaho Palouse-Central Panhandle Mountains-Washington Palouse-
Including the following locations Moscow, Plummer, Potlatch,
Genesee, Kellogg, Pinehurst, Osburn, Wallace, Mullan,
Fourth of July Pass, Dobson Pass, Lookout Pass, Pullman, Colfax,
Rosalia, La Crosse, Oakesdale, Tekoa, and Uniontown
434 AM PST Fri Feb 8 2019

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 1 PM PST SATURDAY...

* WHAT...Snow. Additional snow accumulations of 3 to 6 inches.
Northeast winds gusting as high as 25 mph.

* WHERE...Moscow, Plummer, Potlatch, Genesee, Kellogg,
Pinehurst, Osburn, Wallace, Mullan, Fourth of July Pass,
Dobson Pass, Lookout Pass, Pullman, Colfax, Rosalia, La
Crosse, Oakesdale, Tekoa, and Uniontown.

* WHEN...Until 1 PM PST Saturday.

* ADDITIONAL DETAILS...Plan on slippery road conditions today
through Saturday morning. Patchy blowing snow could reduce
visibility.

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.