Snow Conditions in the Negatives

SNOWPACK OBSERVATION
Negatives, Hemlock Ridge
Submission Info
Volunteer Observer
Tuesday, January 28, 2020 - 6:15pm
Red Flags: 
Recent loading by new snow, wind, or rain
37° 43' 49.9116" N, 119° 6' 3.3048" W
Snowpit Observations
More detailed information about the snowpack: 

Went for a tour in the June Lake lift-accessed backcountry.  Skied from the top of J7, toured up the hourglass, skied an E facing chute in the Negatives, skied the N facing trees off Hemlock Mtn down to the 4 seasons. 

The day started out mostly cloudy and cleared up as the winds picked up.  Calm W winds gave way to moderate NW winds by the afternoon.  We saw light to moderate snow transport in areas that had enough snow to be stripped.  We saw snow moving down the hourglass, blowing into/over NE facing terrain in the Negatives cirque, and up the gut of Yost Creek, but didn't see any snow moving into the E facing terrain in Negatives (which we skied) or the Dream Peak Cirque (which skied past and saw from below).  If the W facing terrain on the opposite side of the ridge had more snow and wasn't already mostly stripped to rocks, it probably would have been moving.  I can't speak with any certainty to loading in the NE facing chutes as we didn't travel there, but that would be my best bet for fresh instabilities.   

A few hand shears on the way up the hourglass (NE facing, 10,000') failed with moderate force.  1cm fresh wind skin, 5cm 1F hard wind slab, F+ snow, P old wind board.  Failures were mostly irregular surfaces in the F+ snow below the wind slab (see photo).  Skiing the E facing chute in the Negatives, we saw very minor sloughing (only an issue because it obscured the rocks while it slid) and small at least one day old isolated wind slabs on the sidewalls of the chute (see video).  Overall the skiing was quite fun and we saw several other parties enjoying the day.  

We saw some minor roller balls off SE facing terrain in the Negative originating near rocks that looked at least one day old.  Other than that, we saw no signs of loose wet slide potential.  S facing terrain that we traveled on consistently had an upper melt freeze (MF) crust (generally breakable) with facets below and a thicker more well established MF crust below.  E facing terrain below 9200' that we traveled on had a MF curst with facets below.  

On Hemlock Mtn, we saw light snow transport from the NW down below treeline as low as 9200'.  On N facing terrain, this had only created a <1cm wind skin that did not affect the skiing quality.  We often felt lightly burried old ski tracks on the way down, but it was still fun.  We skied dense powder/occasional dust on crust down to 8400' and then sampled some of the Sierra's finest trapdoor breakable curst: strong 2-3cm MF crust over 10cm + of loose facets on NE, N, and NW slopes all the way to the road.    

We were out of the steep complex terrain by the time the wind had become moderate and changed directions, so the uncertainty has grown since our travels.  

Snowpack photos: 
Snowpit videos (tests, etc): 
Weather Observations
More detailed information about the weather: 

11:10am: 9600', air temp: +2C, 2/3 clouds, calm W wind.  

12:45pm: 11,000', air temp: 0C, 1/8 clouds (only on the horizons), light to moderate WNW winds.  

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