San Joaquin Mtn, Negatives
Saturday, March 17, 2018 - 2:45pm
Noted extensive avalanching throughout the Negatives but not elsewhere along the ridge. It appears that portions of the Bowl that encompasses the Negatives failed independently, primarily N-NE aspects with a few exceptions. Many of the crowns were only barely visible, likely occurred early or mid cycle. Limited debris visible but most of the avalanches ranout onto the bench above the meadow at the bottom. Negative one failed early or mid cycle, the debris mostly stopped on the bench but a small ribbon continued to the valley floor. Many of the apparent crowns were below steep faces or cliffs and had significant southerly fetches. The largest avalanche D3(+?), R2 was directly under the cliffs on the south end of the Negatives ( ~6’ X ~400’ X ~1000’). My suspicion is the combination of heavy snowfall and wind loading was the prime contributor for most slides with the exception of the largest release, which likely failed at the graupel layer from 3/14. The majority of the slides occurred on N-NE aspects, elevations 10000’ to 11000’. Given the recent avalanche activity, declined to do a crown profile until the avalanche hazard declines a bit more given the active wind loading during the day. This includes the normal approach route. A party of skiers who ventured up into the Negatives reported settlement at the Hourglass but no other activity.
1, D3.5, R2 (NE Aspect, Elev. 10.600', Crwn Ht ~6', ~400’ X ~1000’)
5+, D2, R1(N-NE aspects, Elev. 10,000' - 11,000', Storm Snow)
Clearing skies after significant storm system. Cloud cover, scattered cumulous and cirrus.