Persistent Slabs in Long Canyon

Location Name: 
Thanksgiving Day tour in Long Canyon
Region: 
Long Canyon Area
Date and time of observation: 
Thu, 11/28/2019 - 11:28
Location Map: 
United States
36° 37' 5.9808" N, 105° 27' 35.19" W
US


Red Flags: 
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain

Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

Went out to look at the new snow that fell overnight before Thanksgiving Day.  It seemed to be an elevational snowstorm with 6+ inches of new snow near and above treeline and only 2 to 4 inches of snow below treeline.  The snow we've received in the last week is settling out and with recent winds is forming supportable slabs that make traveling easier.  Winds were surprisingly calm with no snow transporting even on ridgelines.  Lots of low density snow is available for transport when the winds do pick up Friday with the next storm. We continue to get collapse and shooting cracks on basal facets on northerly aspects.  

West and South aspects had the shallowest snowpack anywhere from 1 to 2 feet with North and East aspects ranging anywhere from 3 to 4' near and above treeline.  Below Treeline the snowpack is still thin.

Stability tests continue to get easy to moderate force to initiate propagation on the weak basal facets, which is to be expected with this poor snowpack structure.  Slopes that don't have basal facets, we are not observing any weak layers.  6 to 10" of new snow from the previous two days fell on variety of layers from crusts on solar aspects to firm wind slabs.  This new snow had not turned into a slab when we were out there, but it can be expected with all this snow available for transport and winds in the forecast on Friday that this new snow will stiffen up.

 

Photo 1: Snowpit at 11,400' on a NE aspect

Photo 2: Travel is getting easier with a supportable slab while traveling on skis.  Breaking trail through the new snow.

Video:   (SEE VIDEOA propagation saw test in the basal facets.

Snowpack photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Light
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
Southwest
Accumulation rate: 
None
More detailed information about the weather: 

Thick, humid cloud on us all day but no new precipatation while we were out there.  Winds were 5 to 10 mph out of the SW on the ridgetops with no blowing snow.  

File attachments: