THIS AVALANCHE ADVISORY EXPIRED ON March 3, 2017 @ 5:21 am
Avalanche Advisory published on March 2, 2017 @ 5:21 am
Issued by Andy Bond - Taos Avalanche Center

CONSIDERABLE avalanche danger exists near and above treeline due to wind slab avalanches.  Avalanche danger is MODERATE below treeline.  Northwest winds picked up in the overnight hours transporting the avalaible snow into soft sensitive wind slabs. Human triggered avalanches are likely today.  Cautious and conservative terrain decisions and route selection are essential today.

 

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.

2. Moderate

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Below Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
    Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
  • 1. Low
  • 2. Moderate
  • 3. Considerable
  • 4. High
  • 5. Extreme
Avalanche Problem 1: Wind Slab
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18 to 30" of snow fell Monday through Tuesday with a little of 3" of Snow Water Equivalent (SWE).  Strong WSW winds during the storm have loaded slopes above treeline especially north and east aspects where slabs are 4 to 5 feet thick. Winds picked up in the overnight hours (high teens) gusting in the 30's out of the NW with a lot of snow still available for transport.  These slabs are sitting on a variety of hard, smooth cursts and may not be bonding well to the old snow surface.  

Carefully evaluate the snowpack and terrain as you travel.  Signs of recent avalanches, "whumphing" collapses and shooting cracks 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 Dry
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Some small loose snow sluffs are possible today on steep wind sheltered slopes.  This should be confined to mostly northerly aspects where colder unconsolidated snow exists.

advisory discussion

Northwest winds picked up in the overnight hours (high teens) and lots of snow available for transport will keep the avalanche danger at CONSIDERABLE near and above treeline today. The bottom up approach around these parts hasn't afforded us the ability to get up above treeline on North or East aspects where slabs are expected to be 4 to 5 deep from the recent storm and strong WSW winds on Tuesday.  Avalanche reduction work on Wednesday did produce some 3' deep fractures on NE slopes.  These slabs were not as sensitive as they were on Tuesday but if you are able to trigger one they are running long distances on the hard crusts below.  

Although not strong winds overnight, wind speeds in the high teens and low 20's are strong enough to transport snow.  We've included near treeline as some of our near treeline terrain acts like above treeline due to cross loading.  As always assess any slope you plan to get on paying attention to areas that look loaded.  Avoid wind loaded pillows and pay attention to "whumphing" collapses and shooting cracks as these are signs of instability.  Lower angle conservative slopes are still really fun to ski and probably the wise choice today.   

North facing slopes in the trees near treeline were not impacted from the warm temperatures earlier in the week as well as sheltered from the strong winds above treeline have an overall poor snowpack structure with basal facets still lurking on the ground.  These slopes should be approached with extra caution as the weight of a smaller storm slab avalanche could be enough weight to step down into these older layers.

 

If you're interested in how much snow we've gotten this year check out our recent blog post.  This was written before this last storm, so add 25.5" of snow and 3.15" of SWE to the totals from February which should bring us right around average!

We have a fresh beacon problem out at TSV for the week of feb 28 - mar 6 - check it out and keep your beacon skills sharp!

If you get into the backcountry, please drop us a line at Taosavalanchecenter@gmail.com or on the "Submit Observations" tab at the top of the homepage.  Your field observations are extremely helpful, no matter how simple, and we thank all of you who have shared.

If you're looking to get some exercise and support a great cause look into the Ben Myers Ridge-A-Thon.  This event has been going on now for 20 Years. Come hike the ridge at Taos Ski Valley March 17 & 18th and raise some money that benefits our community!

recent observations

Wednesday was a sunny and calm day.  A cold clear night on Tuesday really dried the snow out and already were seeing these storm slabs settle and consolidate especially below treeline.  We were able to get up around 12,000' on a West aspect where we found a little more than 2 feet of storm slab sitting on a knife hard melt-freeze crust.  In snow pits we were not able to initiate collapse or propagation in the storm slab See Video. However, inbounds control work at TSV on Wednesday did produce some 3' storm slab avalanches mostly on northerly and East aspects.  These were more stubborn than the widespread instability from Tuesday.    

STORM RECAP:  Storm totals ranged from 18 - 30" of new snow with about 3" of Snow Water Equivalent (SWE). Strong SW winds gusting into the 60's also accompanied this storm adding to storm totals especially above treeline. Tuesday was an active day with widespread "whumphing" collapses and shooting cracks as well as remote triggering storm slab avalanches See Video.  18 to 24" of snow was observed while touring in the Williams Lake Area.  Snow fell all day ending in the afternoon evening hours with graupel.  We stayed below and near treeline but the strong winds could be heard howling up above us.  The snow that fell Monday night into Tuesday had some body and weight to it even though it was still pretty low density.  This subtle density difference between the couple of inches of snow that fell in the morning on Monday was all that was needed to create a weak layer.  We were remote triggering storm slab avalanches from 100 yards away that typically were wanting to run on slopes 35° or steeper. Peak instability seemed to be around the mid morning hours on Tuesday.  Visibility was such that we weren't able to get great observation from above treeline but there were reports from inbounds of 4' natural storm slab avalanches.  All indications were that it was just the new storm snow running on the old snow interface. Wednesday should provide us with better visibility and the ability to get better observations.   

Monday brought us an unexpected 3-5 inches of low density snow in the mountains, accompanied by strong W winds.  These winds were building touchy ridgetop cornices and creating unstable surface conditions on steep rollovers and convexities.  Check out Andy's video explaining Monday's findings.   We found the new snow was not bonding well to the underlying crusts, and although there was not much weight to move around yesterday, that will certainly change today with more snow and wind.

Pic: Small storm slab avalanche that we remote triggered 100 yards away

Pic: Snow pit showing the low density snow from Monday morning, with the slightly denser storm snow sitting on top.  Avalanche debris above the pit that we triggered from below.

Pic: Snowpit from West Aspect around 12,000' from Wednesday

Pic: Some of the widespread collapse and shooting cracks we were getting Monday in our travels.

Weather and CURRENT CONDITIONS
weather summary

High pressure aloft will gradually build to our west.  Another chilly start to the morning will give way to milder temperatures and an abundance of sunshine today. Although winds picked up last night (15 - 20 MPH), the winds are supposed to quiet down today (5-10 MPH) out of the NW. Tomorrow will bring another sunny New Mexico sky with even warmer temperatures.       

Weather observations from the Wheeler Peak Wilderness between 9000 ft. and 13000 ft.
0600 temperature: 14.6 deg. F.
Max. temperature in the last 24 hours: 18.9 deg. F.
Average wind direction during the last 24 hours: NW
Average wind speed during the last 24 hours: 15 mph
Maximum wind gust in the last 24 hours: 33 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 93.4 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Albuquerque NWS
For 9000 ft. to 10000 ft.
Thursday Thursday Night Friday
Weather: Sunny Mostly Clear Mostly Sunny
Temperatures: high to 37 deg. F. low to 12 deg. F. high to 42 deg. F.
Wind Direction: W SW SW
Wind Speed: 5 - 10 5 - 10 5 - 10
Expected snowfall: 0 in. 0 in. 0 in.
For 11000 ft. to 13000 ft.
Thursday Thursday Night Friday
Weather: Sunny Mostly Clear Mostly Sunny
Temperatures: high to 29 deg. F. low to 10 deg. F. high to 36 deg. F.
Wind Direction: NW SW W
Wind Speed: 5 - 10 5 - 15 10 - 15
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.