24-25

Toured up the Boundary of Yellowstone Park today. Performed stability tests on two different aspects at two different elevations and these were our results.

1. 9100', South aspect, 120HS, Rounded FC at base. Recent storm interface found small .5mm FC 40cm down but no test results on that layer. ECTX
2. 9800', West aspect, Hs190cm, ECTX, LOC 110cm down, old MFcr/Facet Layer

No recent avalanche activity seen. One large collapse near a ridge line with thin snowpack (<70cm) 

Deep Slab on Northern aspects still a player. Rounding Basal Facets found on South and West aspects

Snow #'s calculated using 6% density

Traveled out the North boundary of Bridger Bowl to Texas Meadow. S1-2 from 1030-1200. S2-3  from 1330 until we ended our day (1600). Moderate to Intense snow transport observed NTL. Loading observed on N & S aspects due to swirling and inconsistent winds. Total snow accumulation of 4" observed during our time in the field. Observed two natural avalanches in steep terrain above Texas Meadows, likely released during periods of high PI combined with wind (SS-R2-D1-N).

I observed at least 4 other natural avalanches in the area, not as big but still a tell tale sign to have cautious route finding and avoid slopes steeper than 30 degrees in this mountain range. 

Very large natural avalanche that ripped out on a NE aspect at 9500ft. It propagated hundreds of feet wide and ran approximately 1500ft. The deepest part of the debris pile was ~15-20ft deep. The crown was approximately 3-5ft deep, maybe deeper. 

Fresh snow had fallen the night of Jan 6th and through the morning on Jan 7th, about 4-6” of low density snow above 8000ft. No wind or recent drifting was observed. New snow from the past storm was 3-4ft deep, basically comprising the entire snowpack, the avalanche failed on a layer of depth hoar at the base of the snowpack.

As I made my way up toward emigrant peak I observed a very large natural avalanche that ripped out on a NE aspect at 9500ft. It propagated hundreds of feet wide and ran approximately 1500ft. The deepest part of the debris pile was ~15-20ft deep. The crown was approximately 3-5ft deep, maybe deeper. 

Observed several large collapses and whoomphing as I toured around the area. I observed at least 4 other natural avalanches in the area, not as big but still a tell tale sign to have cautious route finding and avoid slopes steeper than 30 degrees in this mountain range.