Esha Peak / Canyon Snowpack

SNOWPACK OBSERVATION
Esha Canyon / Esha Peak 3rd Chute
Submission Info
Saturday, January 25, 2020 - 12:00pm
Red Flags: 
Esha Canyon 37° 31' 26.436" N, 118° 48' 4.2048" W
Snowpit Observations
More detailed information about the snowpack: 

Group of two - skier and splitboarder - headed up McGee Creek Canyon with the objective of hitting the McGee Creek Chutes.  In the days leading up to the tour, we noted the reports of variable snowpack from the community. We certainly found plentiful evidence of that variability and a couple of isolated areas of concern.  

There were also some concerning observations just across the canyon the day prior where a large slope collapsed with a shooting crack.  After some quick consideration at the trailhead, we decided that the alpine snowpack on Esha might be a bit more solid than the thinner treeline snowpack in the McGee Creek Chutes.  The chutes are comprised of thin strips of snow between the rocks and many pockets of hanging snow in the adjacent/above rock bands. This area, we thought, could be more likely to feature the more collapsable snowpack structure, versus a thicker snowpack above treeline.  

We were able to drive a subaru with low clearance to the place where the pavement ends.  From here, headed to the usual creek crossing and up Esha Canyon. Snow was soft, refrozen powder with some spots of windboard/sun crust down low.  When we got up about 1000’ into the canyon, winboard became predominant. 

At 9600’ we dug our first hasty pit.  165cm snow depth, of which we dug down to about 120cm.  Found the robust crust layer here that was very difficult to shovel out.  There was 60cm of 4F snow on top of 70cm of pencil/knife hardness facet/crust layers.  The top of the snowpack was very, very well bonded to the crust below. On a hand shear, force was added until the hand pulled straight through the column with no results.  ECT tests showed no results (ECTX) other than the softer snow at the top of the column crumbling under shoulder tap force. This area looked pretty good!

 

Continued up the canyon to the base of Esha, where the snow transitioned from windboard to a softer wind pack.  Dug another pit at 10,800’ below 3rd Chute (center line to summit). Snow depth was 255cm and we dug down about 150cm of that total depth until we hit very hard snow (note, when we did puncture the very hard snow with a probe, there were facets/crusts underneath to ground).  We performed several tests to assess the snowpack before we started our climb. Hand shears were failing at an inconsistent depth with moderate force. This was the old stubborn windslab on top of the crust/facet combo layers beneath. These failures were Q2/Q3 and not overly concerning.  We ran an ECT to check how much force it would take to activate these layers. We were able to get a crack to shoot part way up the column towards the shovel at ECTN27 from a depth of about 65cm. This was not surprising or overly concerning, and we continued up the chute. 

 

Booting conditions were overall solid and climbing was fast.  When we reached the final bend in the chute that heads to the ridgeline at about 12,000’, we encountered a pillowy and hollow wind slab in a steep convex slope above us.  We paused to run some hand shears and produced some results that ultimately prompted us to turn around. In this particular, isolated area near ridgeline, we were seeing the top 15cm of wind slab fail on rounded facets between the slab and a crust below.  Some of these failures occurred on column isolation, whereas some required light-moderate force. This would have the potential to be deeper with the visible slab just above us where loading was evident. For those familiar with this particular spot, it’s somewhat exposed to the rock bands that line the chute below as fall line bends skiers left.  A small pocket could have some pretty serious consequences if it pulled a skier into these rocks, and given that it was already 2p, we transitioned and skied back to the car.

 

Conditions were overall pretty good on the ski down.  The sun had warmed much of the canyon and snow was soft.  The chute on Esha was good wind packed snow. Overall fun day in the mountains!

 
Snowpack photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
Clear
Air temperature: 
Above Freezing
Wind Speed: 
Calm
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
Accumulation rate: 
None
More detailed information about the weather: 

Beautiful sunny day with no wind, temps above freezing but still cool on the upper moraine

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