McGee Mtn - Melt-Freeze, Variable and firm

SNOWPACK OBSERVATION
East Gully
Submission Info
Forecaster
Thursday, December 19, 2019 - 3:15pm
37° 34' 10.7616" N, 118° 48' 38.7504" W
Snowpit Observations
More detailed information about the snowpack: 

Toured up the East Gully of McGee Mtn this afternoon to check out conditions and wind slabs.  Beautiful sunny day with light westerly breeze at the ridgetop at 10,700' (air temp -2°C at 3:30pm).  Very variable wind-effected surfaces throughout, and melt freeze surfaces up to ~9800' on NE aspects, and much higher on ESE to SE aspects.  At 1:45pm SE - ESE aspects up to 8200' were still moist and had not completely re-frozen (but definitely had by 4pm).  A few large rollerballs were also seen ~8500-9000' below NE facing slopes that originated from rock bands that heated up from the sun in prior days (see attached pic). The upper ~1,000' or so were extremely firm, ski crampons or boot crampons being essential ... 5th class skinning at times even with ski crampons.  For the most part a very shallow snowpack outside of the gut of the gullies, but areas of deep wind deposit up high as well.  Dug a quick pit ~10,500' to see what the overlying extensive wind slab was sitting on, and probed the snow depth at 190cm.  The surface wind slab was 50cm thick, pencil + hardness, and was sitting on a 1finger+ layer.  It took quite some chiseling with the shovel to dig down 80cm, so did not try and isolate columns here.  Dropped down to 10,000' and dug another quick test pit on the side of the gully on a ENE aspect where the windslab was thinner and the snowpack shallower.  Here 8cm of Pencil+ windslab sat on loose fist hard faceted grains.  Extended column test failed easily and propagated across the column.  While this test result on its own is concerning, it would be a rare and very isolated area such as sitting above a cliff where the slab is unsupported, where a human could trigger an avalanche.  Looking at all the other factors such as the slab being well bridged and supporting itself in thicker areas and in thinner areas not having enough mass above it, and no new loading in over 4 days, the overall stability in the area I would say is quite good.  Add 2-3ft of snow and that story could change, and those thinner areas could act as trigger points for a large avalanche.  Much more concerning today was not loosing an edge skinning up, as a fall would have been extremely hard to self arrest.  

After the skin up, we weren't looking forward to the ski down.  But it was actually quite edgeable for the most part (save for the patchwork of frozen glean in the upper half that was negotiatable), was only punchable and breakable in a handful of spots, and in the late afternoon the lower slopes had refrozen and were supportable as well.  Skiing thru the low elevation sage brush was a fun obstacle course.      

*McGee creek Rd is driveable to the pack station with 4 wheel drive.   

Snowpack photos: 
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