Observation Date: 01/22/2019
Route/Location:
Up and down Big St. Joe via Southeast face.
Weather:
Wind:
New Snow:
Avalanche Activity:
One crown on steep windloaded E. facing slope around 6,500 feet which appeared to be caused by rapid wind loading on Sunday. Only about 50 feet wide and confined to the new snow. I think we would have seen more rapid loading crowns if visibility was better.
Other Comments:
We dug a pit on 1/21 on the SE face of Big St. Joe around 7,500 feet on a wind loaded open slope. We only dug down to the January 11th interface at 40cm to investigate the new snow. We had ECTN5 at 5cm (new wind crust), ECTP11 at ~20 cm (January 13/14 interface, and we were getting shooting cracks at this interface), ETCN25 at 40cm (the slab collapsed above the January 11th ice crust but did not propogate along the crust). The pit confirmed our observations that overnight snow had not bonded, but that underlying layers had bonded well. I returned on 1/22 and it was much windier than expected above about 7,000 feet, with sustained winds up to 50mph along ridgelines. I didn’t dig a pit on the 22, but was getting a lot of shooting cracks on wind loaded slopes and avoided avalanche terrain.
Observer: Brian Story