Snowpack Summary published on December 7, 2019 @ 5:51 am
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This snowpack summary is valid for 24 hours
Issued by Andy Bond - Taos Avalanche Center

bottom line:

Supportable slabs on top of depth hoar near the ground on North through East aspects near and above treeline continue to be the concern. Avalanche activity has diminished in the last week, but this suspect snowpack structure remains as we have all the ingredients for an avalanche. Take the time to dig down into the snowpack to assess whether the slope you plan to play on has this problematic snowpack structure.  

Avalanche Character 1: Persistent Slab
Persistent Slab avalanches can be triggered days to weeks after the last storm. They often propagate across and beyond terrain features that would otherwise confine Wind and Storm Slab avalanches. In some cases they can be triggered remotely, from low-angle terrain or adjacent slopes. Give yourself a wide safety buffer to address the uncertainty.

Large faceted weak snow on the ground remains on North through East aspects near and above treeline.  This weak layer has become less sensitive in the last week as avalanche activity has diminished.  The fact remains that this problematic snowpack structure still exists on many slopes as we have all the ingredients for an avalanche where we have weak sugary snow on the ground with stiffer slabs on top.   These are also the slopes that will be the most appealing to ski or ride on. Stiffening slabs near the surface will feel good underfoot but the problematic layer is deeper down in the snowpack.  Take the time to dig down into the snow as this will be only way to assess whether this strong over weak snowpack structure exists. The handle of a ski pole or an avalanche probe can also be a useful tool to feel for these layers.

Snowpack Discussion

4 - 6" of snow on Thursday really improved skiing and riding conditions.  Most of this snow fell as graupel and is not a concern right now as it sits on the surface. The added weight of the graupel was not enough to test the weak faceted snow near the ground that we have in many places. Even with moderate winds on Thursday the graupel was redistributed on the snow surface but was not developing into slabs.

 Graupel pooling below cliffs on Thursday

Our snowpack is quickly faceting near and below treeline as cold temperatures at night and a relatively shallow snowpack ( 20 - 100 cm) is driving strong temperature gradients.  Near treeline we have a deeper snowpack with supportable slabs that make for easier traveling.  In many places on north through east aspects these slabs rest on top of weak cohessionless facets. Stability tests continue to indicate moderate force to get these weak facets to fail, with the ability to propagate.

 

 

Near Treeline NW aspect at 11,900' 2mm facets on the ground with a supportable 1 Finger to 4 Finger slab above.  

Above treeline in the alpine the strong WSW winds last week have done a number on our snowpack.  South and West aspects have significantly less snow with previous strong winds stripping the snow from these windward slopes.   North and East aspects hold the most amount of snow right now (100 to 180cm in spots).  These aspects in most places have a series of slabs of wind packed snow from previous strong wind events. 

Deeper snowpack above treeline on a NE aspect.  

 

Stay safe out there and our next update will be Sunday.  If you get out, shoot us an observation as this only helps the forecast.

recent observations

Below Treeline we have a shallow snowpack (20 to 50cm) .  This snowpack is less supportable and quickly faceting. There are still many natural obstacles still visible.

Near Treeline we have a deeper snowpack (40 - 90 cm) with supportable slabs that make travel easier.  This snowpack is also faceting and poor snowpack structure can still be found on northerly slopes where October snow continues to linger.  Stability tests continue to indicate that large faceted crystals on the ground will fail with moderate force and has the ability to propagate with a stiffening slab above. 

Above Treeline  We have a deeper snowpack on North through East aspects.  Firm stiff slabs formed from a series of 3 strong West wind events at the end of November.  Many of the North facing slopes that ran during the avalanche cycle on 11/30 have filled back in and have a shallow snowpack that is quickly faceting. Distribution of the snow above treeline is more variable where some slopes have deeper snowpacks (150cm) and others are quite shallow.

Weather and CURRENT CONDITIONS
weather summary

It was another clear night with high cirrus clouds moving in during the day today in front of a Pacific low that will arrive in New Mexico on Sunday.  West winds will increase this afternoon front of the storm with breezy conditions.  Temperatures will warm throughout the day and snow levels will remain relatively high around 8500' early Sunday morning when snow is expected to start falling.  We could see 6 to 12" in the mountains by Monday morning. 

Weather stations are currently down this morning     

Weather observations from the Wheeler Peak Wilderness between 9000 ft. and 13000 ft.
0600 temperature: - deg. F.
Max. temperature in the last 24 hours: - deg. F.
Average wind direction during the last 24 hours: -
Average wind speed during the last 24 hours: - mph
Maximum wind gust in the last 24 hours: - mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 45 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Albuquerque NWS
For 9000 ft. to 10000 ft.
Today Tonight Sunday
Weather: Partly Cloudy Partly Cloudy Mostly Cloudy with a chance of snow showers
Temperatures: 39 deg. F. 27 deg. F. 33 deg. F.
Wind Direction: W W W
Wind Speed: 10-20 10-25 10-25
Expected snowfall: 0 in. 0 in. .5 - 3 in.
For 11000 ft. to 13000 ft.
Today Tonight Sunday
Weather: Partly Cloudy Partly Cloudy Mostly Cloudy with a chance of snow showers
Temperatures: 28 deg. F. 19 deg. F. 28 deg. F.
Wind Direction: W W W
Wind Speed: 5-15 increasing to 10 - 25 in the afternoon 10-15 10-25
Expected snowfall: 0 in. 0 in. 1 - 4 in.
Disclaimer

This snowpack summary applies only to backcountry areas. Click here for a map of the area. This snowpack summary describes general avalanche conditions and local variations always occur. This snowpack summary expires in 48 hours unless otherwise noted.

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