THIS AVALANCHE ADVISORY EXPIRED ON March 26, 2017 @ 5:28 am
Avalanche Advisory published on March 25, 2017 @ 5:28 am
Issued by Andy Bond - Taos Avalanche Center

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2. Moderate

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Below Treeline

MODERATE avalanche danger exists at all elevations today.  Isolated areas could have a greater danger today.  Loose wet, wind slab and persistent slab avalanche problems are expected today. Evaluate the snowpack and terrain carefully, identifying where avalanche problems exist. Avoid slopes where these problems exist.  

  • 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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About 2 feet of snow fell during this storm with about 2.5" of Snow Water Equivalent (SWE). WSW winds during the storm shifted to the NW on Friday where the newly fallen snow was being transported into wind slabs near and above treeline. Some wind slabs could become increasingly unstable with the strong March sun rapidly warming these newly formed wind slabs.   Carefully evaluate the snowpack and terrain as you travel, looking for recent avalanches, "whumphing" collaspses and shooting cracks as these are indications of an unstable snowpack.  If you observe any of these bulls-eye clues, adjust your travel to lower angle terrain.   

Avalanche Problem 2: Loose Wet
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Widespread loose wet avalanches will become likely today at all elevations as the intense spring sun warms up the new snow for the first time.  Slopes with the largest concern will be solar aspects that are receiving direct sunlight, but don't rule out north aspects that receive some sun right now. Look for obvious signs of instability like rollerballs and pinwheels. Avoid steep high consequence areas or terrain traps like gullies as some of these could be large enough today to be a real concern for backcountry travelers.

Avalanche Problem 3: Persistent Slab
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Even with a return to winter and colder temps there are some weak layers buried in the snowpack that were formed from the warm stretch these past two weeks.  Our snowpack went through a major transition these last two weeks with warm temperatures producing weak wet snow and a weak structured snowpack near and below treeline in most spots. On Thursday temperatures were still well above freezing before we addedd 2.5" of water weight to this already weak snowpack. As we transition back to winter this old snow will take time to adjust and recover.  This first storm added a tremendous amount of weight really quickly and might be too much for the old snowpack to handle. This is challenging right now as slope to slope variations exist.  Dig down into the snowpack to identify if the slope you plan to be on has a weak layer buried below a small crust.  A smaller wind slab or loose wet avalanche also has the possibility of stepping down into older layers or potentially to the ground in spots in shallow areas below treeline. 

These are challenging times as we transition back into a winter snowpack.  No need to rush into things as we let the snowpack adjust. 

advisory discussion

The first in a series of three storms left our area on Friday dumping 2 feet of snow and about 2.5" of Snow Water Equvialent (SWE). It was only two days ago that we seeing high temperatures that we'd typically see in May.  As we transition back into winter so to will our avalanche problems with a return of wind slab and persistent slab avalanche problems.  The second storm arrives Saturday night, producing light snow fall before a more potent storm enters our area for Tuesday.  We'll have to recondition ourselves back into winter and typical March avalanche problems as it appears winter isn't done with us yet!

Challenging avalanche conditions exist today (See Video).  We have MODERATE avalanche danger at all elevations, with three distinct avalanche problems; loose wet, wind slab and persistent slab avalanches all possible or likely today.  With a scarcity of powder in the last couple of weeks, we're all tempted to get our powder fix, but today is not the day to jump onto some of the bigger lines as we let the snowpack adjust to the big storm we just got.

Loose wet avalanches will be the most apparent today as the recently fallen snow will warm quickly with the strong march sun and warming temperatures today.  This is different than the wet avalanches we were dealing with a couple days ago. The 2 feet of new snow will loose cohession today pretty quickly and could potentially be pretty large.  All aspects and elevations could be impacted with low elevations and slopes seeing direct sun the most problematic.  Avoid steep slopes, and areas below rock bands that have high consequence terrain or potential terrain traps like gullies.

Wind slabs have formed near and above treeline on Friday and will be possible to trigger today.  These wind slabs will be weakened by the strong sun today and NE-E-SE could be the most concerning. A potentially bigger concern are weak layers below the storm snow. Two weeks of warm temperatures and intense snow that proceeded this storm did a lot to weaken our snowpack.  Although temperatures dropped below freezing at all elevations before the storm producing a small melt-freeze crust, wet weak faceted snow exists below this crust in some spots (See Photo in Obs).  These layers are now buried and well insulated by the storm snow and colder temperatures at night.  These weak layers should persist as our snowpack transitions. What makes this challenging is that not all slopes will have this problem. Dig down into the slope you plan to play on and assess whether these weak layers exist. Avoid slopes were these weak layers are present.     

 We will issue the next advisory on Sunday morning, and if you get out into the backcountry, please share any observations with us at toasavalanchecenter@gmail.com or on the "submit observations" tab at the top of the homepage - and Thank You!

Events and Happenings:

Thanks to everyone who joined us at Taos Mesa Brewing on Wed night, and THANK YOU KERRY JONES for an awesome presentation on weather and climate - he says it's gonna dump this spring gang!

Many of you have been asking and we are going to be teaching a Level 1 avalanche class Friday March 31st - Sunday April 2nd.  For more information please email Andy or Graham at andy@taosavalanchecenter.org or graham@taosavalanchecenter.org

recent observations

24" of snow Thursday night into the morning hours of friday.  Lots of natural storm slab activity in the early morning hours on all aspects and elevations.  Explosive results at TSV on Friday were also producing size 2 storm slab avalanches (See Video). Didn't have any reports of human triggered avalanches in the backcountry, but with the road closed in the morning and arduous trail breaking there wasn't many out there.  Winds were out of the NW on Friday with apparent wind slab development near and above treeline.  NW wind was a shift from the WSW wind during the storm.  The sun started popping out in the afternoon with loose wet rollerballs on West aspects and low elevations.  We were able to find wet facets below a weak melt-freeze crust that was a major layer of concern.

Pic; Snowpit from Friday on an East Aspect Near Treeline.

Pic; A return to winter! nice to not be skinning on pine bows anymore.

Pic; NW winds filling in our skin track Near Treeline

Pic; warming from before the storm that shows the wet faceted weak layers that are now a persistent slab problem in our snowpack

weather

Today will bring sun and warmer temps as we have a transition day between the first and second storms.  Winds will be light to moderate 5-15 MPH out of the SW today before shifting to NW tonight as a weak disturbance enters our area tonight from the north.  This second storm looks to be weakest of the bunch as a more potent storm bringing with it moisture from the Gulf of Mexico arrives on Tuesday.  The March sun will be intense today as temperatures will approach 50 degrees at lower elevations.  

Two-Day Mountain Weather Forecast Produced in partnership with the Albuquerque NWS
For 9000 ft. to 10000 ft.
  Saturday Saturday Night Sunday
Weather: Mostly Sunny in the morning then becoming partly cloudy. Partly cloudy with a slight chance of snow Mostly cloudy with chance of snow showers in the morning and rain showers in the afternoon.
Temperatures: high to 50 deg. F. low to 26 deg. F. high to 45 deg. F.
Wind direction: SW W NW
Wind speed: 5-10 5-15 5-20
Expected snowfall: 0 in. 0.1-0.7 in. 0.4-1.1 in.
For 11000 ft. to 13000 ft.
  Saturday Saturday Night Sunday
Weather: Mostly sunny in the morning then becoming partly cloudy Partly cloudy with slight chance of snow showers Mostly cloudy with chance of snow showers
Temperatures: high 35 deg. F. low to 21 deg. F. high 29 deg. F.
Wind direction: SW SW NW
Wind speed: 5-15 10-15 10-20
Expected snowfall: 0 in. 0.1-1.1 in. 1.4-2.4 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.