Snow Observations List

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. 

We toured up Lick Creek today. The temp in the parking lot was 17*F, temps warmed as we climbed up out of the valley. At the top of the ridge at roughly 8450’ the temp was 45*F in the shade according to my zip o gauge thermometer on my back pack +/-. The snow was wet and heavy, ski quality was mediocre to poor. The conditions were stable with nothing moving and lots and lots of buried tracks. There was lots of glopping on the skins! It was quite a problem. The ski out was ok in the track but sticky elsewhere making making things somewhat challenging. Back at the parking lot at 3pm it was 15*F. The last 100’ to the car was cold powder.

I have never seen an inversion quite like that!

sorry no pics or video.

Thank you for the work you do!

I hope this is useful and not redundant.

Jon Goodman

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.  

I went for a walk up the main fork of hyalite today and observed a very dirty snow surface from the strong SW winds, also the cornices are growing rather large from the recent wind

as the day progressed the snow surface became moist on any aspect that the sun kissed along with roller balls coming off rocky terrain 

The dry powder took a beating from the warm temps in the alpine 

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. 

From FB Messenger: re-entry triggered avalanche in the Lionhead area (R1,D1)

During a full day of ski touring near Round Lake, we saw about 4" of new snow. Hard to tell though because the wind was really blowing snow around. I saw two small shallow wind slab avalanches but vis was poor.

Toured up into the basin below Emigrant to take a look around. HS varied from about 30 cm in wind stripped areas to 100cm around 8000 feet. On a NE aspect at the same elevation we found about 4in of new snow over a slab sitting on a faceted layer, which did not move easily in a hand shear. Heard from another party that they had no results in a pit in a similar location. Large cornice formation on E facing ridge lines. We stayed down low and had great supportable skiing. 

We went to the Taylor Fork area and into Cub/Cabin Creek to see what snow surface was buried by recent snow (about 0.8" swe in this area).

It was easy to find small facets in every pit we dug (some had surface hoar as well). We looked at N, SW, W, and E aspects at elevations around 9000 ft. On a north aspect, they were 1mm facets chained together almost 10mm long.

Consistently these weak layer were 8-10" deep (more in areas with drifting). They produced easy ECTP's and one ECTPV.

What was remarkable is that this layer produced shooting cracks all day long. They were generally subtle but would shoot 10-50 feet.

WHAT TO DO? Now is time to shift our mindset to "stepping back". Lots of great powder is on the way. Unfortunately this snow will likely come with a lot of wind. The more snow/water and wind that come, the bigger of a step back, we'll need to take in our terrain choices. By the end of the week, we will likely be avoiding all avalanche terrain including runout zones in areas that get 3-4" of swe.

Skied south of Cooke over the weekend. Winds were L-M gusting to X out of the W, SW. 19" HN at 8500' from Friday night to Sunday afternoon. Small, localized cracking of wind slabs, but they weren't as reactive as I would have expected. No avalanches seen, although visibility was limited. There are some density changes within the storm snow, including a layer of graupel. Storm snow was not reactive in hand pits. On solar aspects, there is a MF crust under the recent storm snow and facets under the crust. The crust varies in thickness depending on aspect and elevation, 1-3cm.

Good mellow dust on crust skiing with 1”-3” of poorly bonded new snow. Widespread shooting cracks observed on new snow interface on all aspects traveled through the day (primarily E and S facing aspects). Lots of wind transport filling in the skin track between laps and creating light reactive slabs ~5” deep in places (see photo) primarily out of the west but generally inconsistent in direction. 

See attached profile and photos.

Buried SH below the 2/1 storm. 1-2cm thick layer buried approximately 20cm deep below F precip particles. Surface snow had some graupel particles in it as well.

Human triggered release of cornice overhang near the weather station on Buck Ridge. Recent activity next to the small release. Crown 1-2’ deep, 40’ run, 75’ across running over the tracks riding underneath in the recent wind transported slab.

Skied north of Cooke City. Lots of cracking and small slabs on pillows. Observed one small wind slab on NW facing slope 9200 ft.

Cracking and isolated pockets of wind slab in Beehive. 

Skied into South Cottonwood basin from Blackmore today. Skiing was sub-par with lots of wind scouring and intense active snow transport. Along with the slides observed yesterday, two recent R1-D1 slides were observed in South Cottonwood Basin: below the Dogleg and on N Twin's west wall via cornice break. No surface hoar, slides from today, or cracking/collapsing were observed. 

Observed a large wet loose (D1) in Zimmer Creek today off SE facing cliffs. Likely happened 1/29. There were also other smaller wet loose avalanches nearby on south facing cliffs 

Wind was rocking in alpine today, fresh windslabs forming and naturally releasing. I could make out 3 on E face, but rough vis with blowing snow. Exposed terrain in alpine had about .5” ice crust from yesterday’s sunshine.

This slab (in pic) released around 11-noon-ish.