THIS AVALANCHE ADVISORY EXPIRED ON March 23, 2019 @ 5:49 am
Avalanche Advisory published on March 22, 2019 @ 5:49 am
Issued by Ben Bernall - Kootenai National Forest

Kootenai

bottom line

You will see small avalanches in steep terrain that is being cooked in the sun on Friday. By the weekend incoming weather will provide cloud cover and reduce the danger of loose wet slides in steep and solar affected slopes. Stay safe by moving to lower angle terrain  or shaded aspects when the sun comes out.

How to read the advisory

You will see small avalanches in steep terrain that is being cooked in the sun on Friday. By the weekend incoming weather will provide cloud cover and reduce the danger of loose wet slides in steep and solar affected slopes. Stay safe by moving to lower angle terrain  or shaded aspects when the sun comes out.

3. Considerable

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

3. Considerable

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

3. Considerable

?

Below Treeline
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
    Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Loose Wet
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Loose wet slides will continue to be the main hazard in the mountains this weekend. Friday will be another sunny and warm day and loose wet slides will be frequent in steep terrain that is exposed to the sun. Expect to see loose wet slides on east, south and west aspects at all elevations. These slides will be most active in steep and rocky terrain. None of the slides we observed were large or releasing large quanities of snow. Avoid being on or below steep slopes that are being heated by the sun and this avalanche problem will be easily managed. Cloud cover will move into the area and will likely decrease this hazard by Saturday and Sunday.

Avalanche Problem 2: Persistent Slab
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We are still finding some evidence of persistent weakness being harbored on high sheltered aspects. It will take alot of force at this point to trigger these weaknesses and I would call it a "low-likelihood" but "high consequence" problem and it is worth thinking about before dropping into a steep north facing bowl. The only way to find out if it is present is to stop and dig a pit. The potential here is more present in the West Cabinets where we are finding two layers of preserved surface hoar.



Pens mark potential weak layer on shaded aspects

Avalanche Problem 3: Glide
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The warm temperatures are starting to cause glide cracks to open up in steep terrain and they will likely continue growing as it gets warmer each day. They don't really care about aspect or elevation. It really comes down to the bed surface they are resting on and how much moisture percolates through the snowpack to lubricate the bed surface. These glide cracks are unpredictable and can result in huge slides when they release. Nobody can really predict if or when they will come down; but, again it's an easy problem to solve. Just don't be underneath them. If you see large, deep cracks on a slope that is being heated by the sun it is time to relocate!



Large cracks opening up in steep terrain with rock slab bed surface.

advisory discussion

Weather and CURRENT CONDITIONS
weather summary
Backcountry Forecast from NWS Missoula issued:
340 AM MDT Fri Mar 22 2019

DISCUSSION: Our next systems are not well organized. First a cut
off low will wander north from the Great Basin and then interact
with a shortwave moving out of the southwest on Saturday. All of
this moving into an area of ridging adds up to light, sporadic,
patchy precipitation this weekend with snow levels falling to
around 5,000 feet by Sunday morning.


Kootenai:

--------------------------- 5000-7000 FT ----------------------------
                      Today        Tonight      Sat      
Cloud Cover           20%          45%          85%      
Hi/Lo Temps           42 to 53     31 to 35     36 to 47 
Winds(mph)            SW  4        SW 10G23     SW  9G21 
Precip Chc            0            0            0        
Precip Type           none         none         snow     
Liquid Amt            0.00         0.00         0.00     
Snow Ratio(SLR)       0            0            10:1     
Snow Amt(in)          0            0            0        

Snow Level            6000         6000         5000     
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.