recent wind loading, avalanche activity and shallow coverage in the June lake Backcountry

I took advantage of the first day of operations at June mtn to ride the lifts and access the backcountry.

It was a warm day today with temperatures above freezing and light northerly winds as I toured from the top of J7.  I took the ridge out towards the saddle between Yost and Glass creeks and climbed to 11,200’ at the top of the negatives via the hourglass. Coverage in the June area is pretty shallow, similar to what has been observed in other parts of the northern forecast area. periotic probing found an average snowpack depth of 40-60 cm and a similar “upside-down” structure in sheltered areas near and below tree line. In more exposed areas above 10,000’ the surface snow is much more wind textured and coverage ranges from bare ground to thick wind pillows.

Along my ascent, I observed a decent amount of recent cornice growth on the ridge of the more northerly facing part of the negatives (skiers right) and a recent avalanche off the ridge where the feature turns and faces more southeast. See phot below. The full extent of the avalanche is difficult to determine because the crown has been filled in by recent deposition from the recent northerly winds, but I would suspect it was a natural wind slab release, likely from our recent strong north winds and I would size it as a D1. However, looking at the path it would have been a very uncomfortable ride. And almost certainly would have resulted in a nasty injury.

The negatives are still a bit shallow for my taste, particularly in the lower two thirds. I chose instead to descend the equally thin but less committing SE facing bowl back to the hourglass. Walking the ridge towards San Joaquin mtn from the top of the negatives I jumped on a few large pillows and was able to break loose several sensitive wind deposits.  4-12” thick and 1F over 4f-. Performing a hand sheer on one of these test slopes I found the overriding wind slab broke under easy force.

Picking my way down to the hourglass through the breakable wind board and shallow obstacle-ridden snow was certainly an adventure and I made sure to move slowly and deliberately. Once through the pinch, the coverage was not much better, and navigating the fallen trees and other obstacles in the lower angle treed descent to the meadow took some careful route selection.

Solar aspects were showing notable signs of settlement and I observed the top 2-3 cm of the surface snow to be moist on my skin across a westerly slope at around 9500’ as I made my way back to the base of J7.