24-25

Shooting cracks on Tick ridge in the Dudley drainage. This slab from my ski cut was about 20” deep and 60’ wide. It’s NE facing so pretty wind blown. I took a gladed path but in more open sections I imagine this would have propagated much wider and further downslope. Probably 35 degrees here.

Today, we had the pleasure of riding with USFS Snow Rangers from Bozeman, Livingston, Gardiner and Cooke City. We rode into First and Second Yellow Mule and Buck Creek drainages. 

Temperatures were warm, topping nearly 40 degrees at the parking lot around 4pm. Strong winds blew all day from the SW, sustaining 30mph at ridgelines. Snow was actively transported all day by winds, and plumes were visible on far away ridgelines and summits. There was around 1.5-2' of new snow from the weekend. Widespread dirt and/or dust was also noted on snow surfaces.

Our primary concern today was slopes where strong winds had formed thicker slabs from recent snowfall. On the headwall of the Second Yellow Mule, we saw two recent wind slab avalanches. These were small (R1 D1), immediately below the ridge, and likely broke late last night or this morning. 

Our snowpits today were relatively anticlimactic. We were curious as to how recently buried weak layers were reacting to the new snow. In three separate locations, we performed multiple tests and saw high scoring propagation in only 2 of 9 total tests. This propagation was difficult to replicate. We had ECTN's within the new snow and on the new/old interface. We found broken surface hoar feathers and facets under the new snow, but even those weak grains were not visible in every pit. That being said, we did not travel into Bear Basin, where, prior to the recent snow, Alex found large, buried surface hoar  (https://www.mtavalanche.com/node/33832). We did not observe any cracking or collapsing. 

Plenty of wind slabs ranging in size on Lionhead ridge and on surrounding slopes. Noticed a few natural slides on the way in, a few more on the way out that were rider triggered. Snow was quite wet by this afternoon @8500’. 

Afternoon ski/ snowmobile tour north of Cooke City today.  Some recent avalanche activity noted on east Mt. Henderson, and NE Miller Ridge.  Photos attached.

Very warm temps today (33F for a high at Fisher Creek, but 47F at 2pm the NE Entrance!)

There is now a widespread dust/ pollen layer on the snow surface from recent strong SWerly winds also.

The new snow was a bit upside-down and sticky today with the warm temps, but still skied well on the right aspects and timing.

I measured the new snow depth up near the base of Lulu Pass and was finding 65cms settled new.  Much less in the lower elevations around Cooke City though.

Also, yesterday we were ski touring up Republic Creek on westerly aspects of Woody Ridge.  I was able to ski cut a small test slope and get a wind slab to crack and move a short distance (6" deep), but aside from that, no other natural avalanche activity noted on west Woody (good visibility in afternoon on exit).  

Also, on our exit yesterday we observed 3 D1 storm slab/ wind slab natural avalanches on east Mt. Republic.  All mid slope, where it is common for cross-loading.  These appeared to be failing at the new/ old interface.

No collapsing noted the last 3 days of ski touring.  

Toured up around fairy lake today, winds were ripping all day. Saw several d1 soft slabs in upper elevation terrain, many of them running quite far. We opted ski a lower elevation zone and were surprised to find a soft slab (d1/r1) that ran on an east facing slope at about 7500’ and about 500-600 ft below the ridge line on a slope just over 30 degrees. 

Sunday, 2/2, excellent trail condition to Independence thanks to SGCRA volunteers. On top around Monument Pk, still have rocks just under the surface.  Excellent riding in the trees approaching Blue Lk and Baboon. This new storm is all we need for prime riding conditions.  

Temperatures -1F at the Base of Bridger Bowl. Rising to near freezing everywhere else.