THIS AVALANCHE ADVISORY EXPIRED ON March 20, 2019 @ 4:53 am
Avalanche Advisory published on March 19, 2019 @ 4:53 am
Issued by Ben Bernall - Kootenai National Forest

Kootenai

bottom line

The avalanche danger will fluctuate from LOW in the mornings to CONSIDERABLE in the afternoon as the sun warms the slopes and reduces the strength of the snowpack. You will see small avalanches in steep terrain that is being cooked in the sun. Stay safe by moving to lower angle terrain when the sun comes out.

How to read the advisory

The avalanche danger will fluctuate from LOW in the mornings to CONSIDERABLE in the afternoon as the sun warms the slopes and reduces the strength of the snowpack. You will see small avalanches in steep terrain that is being cooked in the sun. Stay safe by moving to lower angle terrain 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

?

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 week as we repeat a continuous cycle of freezing and thawing. Yesterday we observed loose wet slides on east, south and west aspects at all elevations. These slides were 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. The snowpack will be spending less time in it's frozen state as each day progressively warms so these slides may entrain even more snow as the week goes on.

Avalanche Problem 2: Persistent Slab
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The past week we have found a widely distributed persistent weakness buried about 11" below the surface, it seems to have survived at the highest and most sheltered locations. Yesterday we observed the evidence of this weak layer on northerly aspect above 7,000' were the warming temperatures caused this layer to release naturally. This weak layer will likely flush itself out and cease to be a problem with the current weather pattern. Best advice, if you find yourself on a high peak getting ready to shred the last bit of cold pow on a north aspect; take a minute to assess the potential, find a safe spot to dig a quick pit to see if this layer is still reactive.

Avalanche Problem 3: Glide
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The warm temperature 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!

advisory discussion

Weather and CURRENT CONDITIONS
weather summary
Backcountry Forecast from NWS Missoula issued:
400 AM MDT Tue Mar 19 2019

DISCUSSION: Temperatures will be slowly warming each day as a 
ridge of high pressure continues to be build over the region. A 
low pressure system will undercut the ridge by the end of the week
causing an increase in cloud cover especially south of the I90 
corridor. An active weather pattern appears to return by the 
weekend. 

Kootenai:
--------------------------- 5000-7000 FT ----------------------------
                      Today        Tonight      Wed      
Cloud Cover           0%           5%           5%       
Hi/Lo Temps           42 to 51     27 to 33     44 to 54 
Winds(mph)            E  5         E  7         E  7     
Precip Chc            0            0            0        
Precip Type           none         none         none     
Liquid Amt            0.00         0.00         0.00     
Snow Ratio(SLR)       0            0            0        
Snow Amt(in)          0            0            0        
Snow Level            5000         6000         6000     
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.