Decomposing Crusts in the Sherwins

Sherwins, trees below the Perch
Submission Info
Volunteer Observer
Friday, December 20, 2019 - 12:45pm
Red Flags: 
37° 36' 36.8748" N, 118° 58' 21.1728" W
Snowpit Observations
More detailed information about the snowpack: 

Went for a tour in the Sherwins this morning with the goal of checking out the distribution and degree of faceting below and within the rain crust and to try to find some decent turns.  The day started out below freezing and quickly warmed up to 4or5C above feezing.  Pretty overcast skys broke up to partly cloudy by 10am.  

We headed to the NE facing trees between Punta Bardini and the Perch.  On the skin up, we were able to switch back and forth between NE, N, and NW facing treed slopes from 8500-9300'.  On each slope, we found varying thicknesses (4-10cm) of 4F hard snow of 1mm angular grains with very weak cohesion (but not none) beneath the rain crust.  The rain crust was sometimes the exposed surface and in most placed covered by a few inches of dense settled powder.  The rain curst was weakest and most deteriorated on the NE aspect; the skis broke through easily and the crust could be broken apart easily by hand.  The crust was a little stronger on the N aspect, but still not supportable.  On the NW aspect, the crust was mostly supportable and firm.  Perhaps the NW absorbed more afternoon heat and retained more heat throughout the night than the N (even more than the NE) and so was subject to a weaker overnight temperature gradient.

We transitioned and skiied the NE facing trees from 9300' down.  The first two hundred feet or so was actually fun where the thin rain curst had deteriorated enough.  Lower down where the crust was thicker and weak, it was breakable and we skied cautiously.  The final stretch back to the propane tanks is still skiing fast, but is starting to get a little patchy with some rocks reappearing.  

Weather Observations
Blowing Snow: 
Air temperature: 
Wind Speed: 
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
More detailed information about the weather: 

0830, -5C with no wind, mostly overcast at the propane tanks.  

1000, +4C in north facing trees at 8900' with no wind, partly cloudy.  Surface temp: -4C

1045, +5C in open north facing trees at 9300' with calm NE wind with occasional moderate gusts. Surface temp: -3C 

-- placeholder --

ESAC receives significant financial support from ...