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From obs: "We also saw some spectacular surface hoar- probably 1-2" tall in places with extremely sugary snow underneath" Photo: USFS Bozeman Snow Rangers

Performed two ECTs and a PST on an E aspect at roughly 9000’. HS was about 50 cm and the old faceted snow below the new snow was obvious. We had two ECTX in adjacent pits and a PST result of 40/100 Arr on the interface of old and new snow. These results were surprising as the snowpack structure had 4/5 lemons and we experienced Whumpfing on the same slope just 100 feet away. We also experienced whumpfs in other locations throughout the basin.

Today I was skiing a south facing slope between 8500-9500 ft near Mt Henderson. I observed at least ten large collapses, some of which sent cracks 30 feet long. This slope had a shallow snowpack relative to the rest of the area. 

We were ice climbing on Mummy 3 and 4 yesterday and as we looked across the valley to Mount Bole, we could see evidence of avalanche activity on the NE aspect of the peak. It looked quite big in length but could tell a depth from that far away. 

We drove and then rode up Little Bear this morning on the 3138 road (also snowmobile route #900).  Once 3138 splits off from 980 there was mostly enough snow for riding on the road without issues but little else.  Snow depth varied from 4-6 inches, down to 2-3 inches in sun and wind exposed areas, to as much as 18 inches or so higher up (8400').  We also saw some spectacular surface hoar- probably 1-2" tall in places with extremely sugary snow underneath; often so sugary we weren't leaving well defined tracks behind our sleds.  As with everywhere else, we heard some collapses while off of our machines.  

Toured up to the lake and dug at 9200ft west facing just up slope from the lake. Failure while trying to isolate the column for a etc on fist attempt.  2nd test was etcp1. Some collapsing while skiing across the flats. Three days ago in middle, had some huge surface hoar as well as big collapsing and cracking.

From email: "We noticed 2 natural avalanches on the east-facing slopes below Bald Peak. I lost count, but we experienced well over 30+ collapses while walking on the ridgeline. Many of these collapses were very large and we were able to watch the slopes 'sink' by upwards of an inch which made our hair stand on end." 12/13 Photo: R. Parsons

Skiers in Liondhead saw large surface hoar cystals on many slopes. From email "some of the largest I've ever seen!" on 12/13. Photo: R. Parsons