Snow Observations List

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. 

Toured out of Pine Creek yesterday and up to around 9000ft. We found large surface hoar crystals around the creek and smaller NSF in most covered areas. In steeper, north-facing terrain, we found a fairly uniform snowpack in areas that had been seeing some wind and surprisingly good surface conditions for skiing. We found a few feet of sugar snow near the ridge line with large faceted crystals lower in the snowpack, restricted to mostly sheltered areas. While traveling, we saw no signs of instability except some wet slides from the past few warm days. However, the snowpack around Pine Creek is much thinner than the rest of the forecast area and is showing significantly more signs of faceting, especially in sheltered areas.

Went out to ski the S facing coulior on Mt Delano yesterday in the Absarokas and figured we’d report back.

In the valleys we found significant surface hoar. Once in higher elevation, widespread crust on all aspects.
On N facings- some wind blown snow above a 1-3 inch crust. Crust on SE-SW facing aspects varied from breakable to very firm. Facets under crust in some S facing areas as well.

Wet slide debris found on S facing slopes as per picture.

Overall a very shallow snowpack, including at almost 8k. It became a rock and downed tree avoidance mission.

Two Point release avalanches on south slope ofTwo Top