THIS AVALANCHE ADVISORY EXPIRED ON January 25, 2018 @ 5:53 am
Avalanche Advisory published on January 24, 2018 @ 5:53 am
Issued by Hannah McGowan - Taos Avalanche Center

Avalanche danger today is MODERATE near treeline and above, where heightened avalanche conditions exist on specific terrain features.  Human triggered wind slab and persistent slab avalanches remain possible after a weekend storm added 10-18" of new snow to our weak and highly variable snowpack.  Evaluate snow and terrain carefully, and avoid travel in areas of concern.  

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.
  • 1. Low
  • 2. Moderate
  • 3. Considerable
  • 4. High
  • 5. Extreme
Avalanche Problem 1: Persistent Slab
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Human triggered persistent slab avalanches are possible today on specific slopes above treeline, and could have serious consequeces.  Watch for unstable snow on steep north to east aspects, including cross-loaded gullies, concave bowls, and beneath ridgelines. These are the places that have been collecting snow since November, where the snowpack is much deeper than other slopes and made of older slabs on top of weak faceted snow.  It may be tough to identify where the old snow was before this weekend's storm, so take the time to dig down and see if you're traveling on slabs that existed before this weekend's storm.  If you find this snowpack structure or experience signs of instability like shooting cracks, whumpfing, and collapsing, then it's best to avoid these slopes.  

 

 

Avalanche Problem 2: Wind Slab
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The winds picked up Sunday night as the storm tapered off, and continued all day Monday, with gusts in the 40's.  With 10-18" of new snow available for transport, wind slabs have formed near treeline and above.  Wind slabs usually have firm or smooth surfaces, and form on the lee of ridgelines, gullies, and other terrain features capable of catching snow from the wind.  Avoid travelling on steep slopes with recent deposits of wind drifted snow.  Any wind slab avalanche would be small, but has the potential of stepping down into older layers creating a larger, more destructive avalanche.  Be aware of terrain traps and ground hazards, which would make even a small avalanche have big consequences. 

advisory discussion

Traveling on your boards is finally possible in certain places after this much needed weekend storm, however thin coverage and excessive ground hazards are still a reality.  10-18" of new snow was added to our weak and variable snowpack, which gave the moderate winds after the storm plenty to work with.  Windslabs formed near treeline and above, capping a snowpack made entirely of facets in some places, and adding a new layer to a stack of old slabs and facets in others.  Wind slabs are typically formed in the lee of ridgelines and crossloaded gullies and can be identified by their wind drifted appearance and smooth or firm surfaces.  

Many of the steep north facing gullies and terrain features above treeline that have collected snow all season have a surprisingly deep snowpack that is characterized by facet/slab combinations.  Slopes with this structure may be tricky to identify, since now they're covered by a fresh coat of snow, but they are the places of most concern today, where its possible to trigger an avalanche that would step down to weak facets at the ground.  Any avalanche today would be of high consequece, considering the amount of ground hazards that are present in our shallow snowpack.  

I hope you didn't store your mountain bikes and rock cimbing shoes too far out of reach, because unfortunately it could be February before we get another taste of fresh snow.  Between now and then we'll keep monitoring the snow we do have, as it will be changing quite a bit.  

recent observations

Widespread collapsing and shooting cracks were observed on Sunday near and above treeline on northerly aspects.  In some instances shooting cracks were running 100'.  In doing avalanche mitgation work on Monday, Taos Ski Patrol triggered persistent slab and wind slab avalanches.

Photo: 1/22 New snow and the affects of wind on No Name  

Photo: 1/20, Right before the most recent storm.  An example of the snowpack structure that is responsible for persistent slab instability, NE slope above treeline.  

Photo:1/20 Large Depth Hoar like this is the major culprit of our instability 

Weather and CURRENT CONDITIONS
weather summary

Very low overnight temperatures of about 10 degrees will give way to yet another unseasonably warm day.  The warming trend that started yesterday will continue through tomorrow, then temperatures will drop and winds will pick up as a storm passes to our north.  It will most likely not affect us with moisture, but its always possible that the storm could dig farther south than predicted.   

Weather observations from the Wheeler Peak Wilderness between 9000 ft. and 13000 ft.
0600 temperature: 8.3 deg. F.
Max. temperature in the last 24 hours: 25 deg. F.
Average wind direction during the last 24 hours: W
Average wind speed during the last 24 hours: 11.5 mph
Maximum wind gust in the last 24 hours: 18 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 20 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Albuquerque NWS
For 9000 ft. to 10000 ft.
Wednesday Wednesday Night Thursday
Weather: Mostly Sunny Mostly Clear Partly Cloudy
Temperatures: 39 deg. F. 15-21 deg. F. 41 deg. F.
Wind Direction: W SW SW
Wind Speed: Up to 15 Up to 15 Up to 20
Expected snowfall: 0 in. 0 in. 0 in.
For 11000 ft. to 13000 ft.
Wednesday Wednesday Night Thursday
Weather: Mostly Sunny Mostly Clear Partly Cloudy
Temperatures: 32 deg. F. 15-20 deg. F. 33 deg. F.
Wind Direction: W W SW
Wind Speed: 5-15 5-15 5-25
Expected snowfall: 0 in. 0 in. 0 in.
Disclaimer

This advisory applies only to backcountry areas outside established ski area boundaries, Click here for a map of the area. This advisory describes general avalanche conditions and local variations always occur. This advisory expires 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the Taos Avalanche Center who is solely responsible for its content.