An account of recent conditions

SNOWPACK OBSERVATION
From Bridgeport to South Lake
Submission Info
Forecaster
Monday, May 20, 2019 - 10:00pm
Red Flags: 
37° 42' 33.8652" N, 119° 6' 19.1664" W
Snowpit Observations
More detailed information about the snowpack: 

Here's a great conditions account from Matt of Alaska's.Achorage Avalanche Center.  The past 1.5 weeks exploring the Sierra.  Thanks Matt for sharing!

Wanted to provide an overview of what I noticed:

5/9: Summited and skied Dunderberg (via SE gully) and Black Mountain (via E bowl and ridge to north face descent).  No instabilities noted.  All corn, even on northerlies, and only wet loose late in day.  Dunderberg SE ripe by 9ish, Black north by noonish.

5/10: Summited and skied Tioga Crest/Dore Cliff (via Lundy Canyon and north slopes).  Dust on crust from late afternoon showers/t-storms the day before down to trailhead elevation.  Actually tried to go up Excelsior first, but it was too icy and no vis.  Clouds lifted as we head towards Dore Cliffs.  Blue alpine ice visible on upper Dore Cliff chutes.  VERY FIRM SLIDE FOR LIFE!  After Dore Cliff, traversed over to Scowden and descended the Dogleg Chute.  It was an interestingly pleasant mix of graupel-like powder up high, transitioning to softening dust on crust in the middle, to corn down low.  Again no recent signs of instabilities noted, as things were locked up from MF cycle and there wasn’t any significant sun this day.  Did notice some older wet slab activity on steep southerly slopes above and in the vicinity of Mill Creek falls.

5/11: Summited and skied Dana via Lee Vining and Powerhouse chutes.  I chose the Powerhouse route, over V-Bowl and Coke Chute, because I figured the north face slopes would hold up better over the course of the extremely sunny day (i.e. not get too soft as more easterly aspects might).  I tried to traverse ridge from Dana Plateau to Dana, but got shutdown by fifth class near Dana Plateau HP.  Dropped a steep and exposed SW chute (it had excellent ripe corn by late morning) into basin below Dana north couloir, and climbed the couloir to E ridge and summit.  E ridge was nicely softened by early afternoon (which was a necessity given the rime formations that would have been horrendous skiing while frozen).  N couloir did not really soften from sun and was wind-blasted slide-for-life for upper 2/3.  Lower 1/3 was a few inches of pow on windboard.  Skinned up a relatively mellow SW chute above Dana Lake back to the Plateau.  It had ripe corn (for great skinning) on top of a bomber MF base that seemed impervious to sun-softening below the upper 2-4".  Tried to descend the skier’s right Powerhouse chute, but it was nearly ice with no softening.  Ended up descending the main, middle chute we ascended.  I was able to ski it, but my partner down climbed the upper 2/3 due to slide-for-life.  Once in the basin below Phouse chutes, it was great corn to the road, with less than 100 yards of dry ground.

5/12: Hiked up to the far side of Parker Lake in trail runners.  Skinned from there up to Koip and Kuna.  All aspects had corned up by afternoon, and there was a few inches of recent snow in the upper elevations from afternoon showers/t-storms in previous days.  Things were quite soft down low by late afternoon, but the corn was still acceptable and not nearly isothermal.  No signs of instability.

5/14: Hiked up from Laurel Lakes trailhead to ~2800m in trail runners before skinning up to Bloody.  Lots of tracks in the main Bloody couloir.  Only 1 set in Y-Not.  Booted up existing track in main Bloody, and skied excellent corn in Y-Not by late morning/early afternoon (main Bloody took longer to soften).  Went back up main Bloody and skied the main couloir.  It had softened nicely by mid afternoon.  Some minor rock fall in the couloirs by late morning.  Folks should be mindful of this, avoid the walls, and wear a helmet!  No signs of instability due to continued MF conditions.

5/17: AMAZING DAY at South Lake!  Got an early start, left the trailhead before anyone arrived, and broke trail through ankle increasing to boot top deep pow up to Thompson.  I climbed the Non-Moynier while my partner skied some laps in the lower half of the Tridents.  The Non-Moynier was thoroughly MANK!  There were anti-tracks noticeable at the top.  It seems like it ripped during the storm, or a previous skier sluffed it out.  Significant amounts of exposed alpine ice, granite, and very icy MF with basically no soft snow.  The entrance of the Non-Moynier had exposed granite and would require a down climb, or skill perhaps beyond even what Vivian Bruchez possesses.  I skinned and booted to the summit, and then went down to ski the Harrington line of the Trident.  The entrance to all of the Tridents was puckering ice, with some blue evident.  After the tenuous slip into the Harrington, it was BLOWER pow!  The sluff was very heavy, which triggered a soft slab (that was almost indistinguishable from the sluff).  This is the “avalanche” that I noticed the guy that followed my skinner (and skied “Mountaineer’s Peak”) submitted to ESAC obs page.  While the sluff was heavy, it was easily manageable (although I understand this may seem relative - but from and Alaskan perspective…).  We then traversed over to Gilbert and climbed the north couloir.  Of note, there was a sizable D2 natural wind slab that had released on a cross loaded ENE feature between the Tridents and Gilbert at ~12300’.  There were also some naturally triggered D1 wind and soft slabs triggered by sun-induced point releases during the day at about the same elevation and aspect below the cliff bands in this area.  At ~12400’, while breaking trail through a more heavily wind loaded section of lower Gilbert N couloir apron, I experienced some cracking - but this was very low energy/high friction.  Stomping in these relatively “safe” areas showed no signs worrisome instability and the cracking was localized to the most heavily loaded areas.  Once in Gilbert N couloir, which had slid during the storm, we were able to boot up the slide path relatively efficiently (it was boot top to knee deep, and not crotch deep like the flanks that had not slid during the storm.  After summiting, we skied the couloir.  The snow was thoroughly BLISSFUL, with heavy but manageable sluff.  No soft slabs in this one.

5/18: Another great day via S Lake.  Followed an existing track, from folks that broke off my track from the day prior, to the upper meadows and then starting breaking trail through not-quite-corn to powder en route to Johnson.  Climbed up the Johnson N couloir that drops from just E of summit.  Worth mentioning, guidebook says Johnson N couloirs are 40* at steepest, but I measured this one up to 52* in three different places.  Followed a sliver of icy snow and granite from top of couloir to E ridge just below summit.  Booted up to summit and skied from summit down the NNW face.  This was a spicy and exposed line.  It generally was covered in a few inches of pow on top of icy MF.  Some jump turns triggered very small soft slabs that had not bonded well to the MF ice.  After threading a line through rocks above the cliffs and onto a ramp, I skied into the wide N facing couloir from the col W of Johnson’s summit at about its midway point.  Perfect pow in there!  I then recycled the N couloir booter with my partner and we skied the N couloir.  Heavy sluff, but no slab.  Worth mentioning: there was some interesting natural avalanche activity noticed on the approach to Johnson, primarily on northerly aspects.  Some steep northerly terrain, primarily below cliffs, had avalanched naturally.  It seems like these were probably slabs triggered by point releases from above.  Also, noticed numerous glide cracks on slopes deeper in the Sierra (above Middle Fork Kings River).  Didn’t noticed any glide cracks on the Eastside in any of the areas I visited.  And: forgot to mention small, skier triggered wet slab activity on very steep rollovers on our mid-late afternoon exits back to S Lake - these only occurred below ~10,500’ and were slow moving and predictable…but something like this could catch the unwary off-guard given the refresh yesterday.
 

Weather Observations
Blowing Snow: 
Air temperature: 
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Air temperature trend: 
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