Snow Observations List

submitted to us via IG: "triggered this large wind slab below Bridger Lift this morning [11/18]. It propagated quite a ways."

18-24” new snow at Lick Creek area

Not much wind. Cold

No instability noted

Supportable base (unlike usual for this time of year)

Went on a tour today with a buddy to check out the snow conditions in the Bridgers. We found cold temps and steady blowing wind while climbing up to saddle, actively loading the east aspect up high. Was able to stomp on new drifts/cornices and see wind slabs crack and go. These slabs didnt propagate more than 6 inches deep, and they moved very slow down hill. Creamy snow conditions but overall looking good (except the rocks). Cheers!

We went down to Sawtelle Peak to do some work on one of our weather stations. Lots of rime on the peak.

While we were down there, we dug a pit to see how the snowpack is developing in the Island Park area. Some wind drifting, but not super dramatic. Dug on an east aspect around 9000 ft off the Sawtelle Peak Road. Snowpack depth was around 4 ft. ECTX results.

It's still early season, but for now we're happy with how the foundation of the winter's snowpack is shaping up.

Toured into upper beehive with intentions of riding some steeper terrain. Widespread wind buff, observed small natural wind slabs that released, seemed isolated to south facing slopes from the recent north winds. Wide spread shooting cracks, however nothing seemed to propagate and slide on small test slopes. 
snow depth varied from 20cm to 100+cm,

generally filled in 

kept our terrain simple 

E-NE 8500ft

Whoomping collapsing and cracking throughout the day  

Wind loading on S slopes 

30cm storm snow

10cm small facets

Shooting cracks and whumpfing observed at Red Lodge Mountain on Little Tree run. Rapid loading with 12"- 15" inches of fresh snow in the last 14 hours along with evidence of wind-loading (drifts and wind-scouring). 

I have been cruising around Hyalite climbing a good deal the last week, and have gotten some good looks up high as well. As you have probably observed as well, things are well set up for this time of year. Snow depths are 50-100cm, right side up, and there has not been much wind transport. Although there has been a good deal of waist deep trail breaking, it's due to there being a lot of new snow, not facet wallowing! Gully features lack a slab, and we have not observed any signs of instability in either Flanders or the Main Fork. There has been a fairly constant trickle of new precip up there, and surface conditions have consistently been precip particles and DFs, although we have occasionally observed surface hoar below treeline. Sam

Dug two pits at Bacon Rind today. Very similar snow structures in both. Shallow and weak but not unstable.

Skied a number of laps in the southern meadows and out the skillet at the end of the day. No signs of instability were noted. Skiing was pretty good.

Rode from Targhee Pass to the weather station on Lionhead Ridge to do some maintenance. Didn't have time for formal snowpack observations, but did get a look at how things are developing.

Snow depth was around 2 ft (in line with Madison Plateau SNOTEL reading), with some thicker drifts and slightly thinner on sunny slopes. Snowpack mostly consisted of snowfall from the past two weeks and didn’t seem to have faceted too much yet. Did find 6" of facets at the ground on one shady slope. Still lots of rocks and bushes showing, but the snowpack was mostly supportable to a snowmobile on the flats.

No avalanches or signs of instability observed.

First tour out in Hyalite today and thought I'd share some quick data I gathered from the Lick Creek saddle.

50-60cm of snow out there with hardly any wind effect on it. 

The quick pit I dug was:

0-25cm F 1-1.5mm faceting rounds

25-27 1F solar crust (easily broken)

27-43 4F 1mm rounds

43-55 F new snow

Cheers!

We toured up to the Fingers and around the corner to Boundary Chute. The snowpack was 1-2.5 feet deep. The pits we dug were 37-60cm. One was in the Fingers Meadow (ECTX) and the second in Boundary (ECTP24 - with low energy and unclean shear 13cm from the ground). The basal layers are faceting but are still 4F+ to 1F hardness. Stability was looking pretty good where we were today. There was a couple of inches of new snow up high, and the mid-mountain wind was transporting it into drifts up to 6” deep. We saw no avalanches or signs of instability, but I suspect a skier or rider could find a drift big enough avalanche in some of the ridge terrain

We observed lots of well developed surface hoar on Chestnut Mountain on top of approximately 12” - 15” of snow. 

A number of Avalanche Crowns on an east aspect at 9500 ft.

Dug a pit at the bottom of the upper meadows at Bacon Rind. 8700ft, got no result for an individual column or extended column, even a shovel shear produced no result. New snow from last weeks storm cycle bonded very well to the old snow from the first October storm. 60-80cm in upper meadows without much of any wind effect. 

We dug three snowpits over the course of two days from 11/12 to 11/13 around Cooke City and found a weak layer 20-30cm above the ground at various aspects and similar elevations. The weak layer was composed of small rounding facets and was less than 1cm thick. The weak layer was at the interface between old and new snow. The old snow below the weak layer was composed of coarse, rounded/rounding faceted grains. The new snow above the weak layer ranged from 60-80cm in height and was right-side-up, progressing from fist hardness at the surface to one-finger immediately above the weak layer. Test results were as follows:

Goose Lake – NE aspect, 10,100 ft (45.11627, -109.92057): ECTP25, 80cm deep. HS 110cm

Scotch Bonnet – SW aspect, 9,800 ft (45.07038, -109.94489): ECTN (*did propagate 60cm deep on "31st" tap, a very hard whack after no formal result). HS 80cm

East Henderson – E aspect, 9,700 ft (45.05855, -109.94966): ECTP29, 65cm deep. HS 90cm

Additional notes: 11/12 had clear skies, no wind, and warm temps. A 5 cm thick sun crust formed on SE, S, and SW aspects. No natural nor human-triggered avalanches were observed on 11/12-11/13. A continuous cornice had formed along the entire N-S ridgeline on the east side of Henderson by 11/13. 

Our group of four went to Bridger Bowl to evaluate the snowpack and get some decent turns. We dug a pit at the bottom of the pitch of hidden gully at 7460 ft and found a graupel layer sitting on an ice crust that was a layer of concern. Since the snow above it wasn't cohesive enough to form a slab we found Q3 fracture quality at ECTP 23. As we transitioned to ski after skinning further up towards hidden gully there was a much more reactive wind slab that formed near the surface. We were at 7990 ft on a ENE aspect and found 5 cm of fresh soft storm snow on top of a 13 cm wind slab that was 4F+ in firmness. The CT results were a Q1 fracture on 1 tap and this was alarming. Our group was ready to ski and for this reason an ECT test was not performed, but this alarming CT result made us rethink our original plan of skiing directly along a wind loaded gully where we found the weak wind slab layer to be. The quick pit that showed this wind slab was dug below a rock outcropping between hidden and northwest passage. We believed this was a concern specific to this terrain feature and that that reactive of a wind slab was unlikely to be found away from this outcropping. We felt that in sheltered and treed areas that aren't getting sluff and wind deposited snow dumped on them because of their terrain features we would be safer. 

It was cold and snowing most of the day with 1-2" of low density new snow by 3pm. We dug 3 pits: at the top of Tyler’s, and top and Middle of Spanky’s. Our pits were 40-70 cm deep and we had ECTXs and a couple ECTNs(23-25) around 30cm above the ground on top of older, slightly more faceted snow. For now stability is generally good with primary problems being wind slabs. It seems the snowpack is shallow enough it will only get weaker without much snow in the forecast.

Skied around Mt. Henderson the last 2 days- 

No avalanche activity observed.

3 snow profiles.  ECTP's in 2 of 3 snowpits.

Also, we experienced at least 6 large collapses while touring the last 2 days, often after 10+ people up the same skin track.

When walking around near grotto falls and below fat and thin chance there was significant surface hoar forming. The crystals near fat and thin chance appeared to be 1mm in size and near the grotto falls parking lot specific areas had surface hoar up to 3 or 4mm in size.