Snow Observations List

From IG Stories: A group on the "Rip Curl" area of Woody Ridge south of Cooke City report ECTP1 test results failing on buried weak layers. 

Felt 2x collapsing or wompfing of the snow in the Two Top area, observed wind scoured terrain with wind slab deposits on the N, NE, E, and SE slopes.  Storm Slab of 6-8" over melt freeze cust. Shooting cracks in front of skis. Light snowfall during the day, overcast skies, and light winds.

Toured to Upper Hyalite Canyon to Divide Peak and we were pleasantly surprised. The layer of weak facets buried almost 2' deep up there has gained some hardness (4 fingers hardness instead of Fist hardness). It produced more promising test scores than we've been seeing in other places.

• ECTN at 9000', NE facing
• ECTP30 at 9560' E facing
• ECTP27 and ECTP23 at 9600' SE facing

We did not experience any cracking or collapsing. There had been strong winds three days ago, but it didn't seem like winds have moved much snow since then and there was lots of great powder skiing.

This is just one observation but it is perhaps a hint that this layer could heal in the reasonable future. Continuing to bury this layer with light snowfall would do it. 

For now, we're cautiously optimistic that we found one place with decent-ish looking snow. Hyalite and the entire Northern Gallatin Range is a large place with a lot of variability and likely many places with plenty of weak snow that warrants digging and assessing the weak layer. 

We skied Middle Basin and Going Home Shoot today. Around 9am, wind was calm with a high OVC cloud ceiling. By 10:30, the clouds rolled in and S-1 to S1 began for about 2 hours. The clouds raised, snow ceased, and the sun peaked through by 12:30pm.

No cracking, collapsing or evidence of avalanches were observed throughout the day. Middle basin skied well with ~6-10” of recent snow in places- the formation of a new snow slab seemed to be in the making. Although wind was calm today, cornices and windboard were apparent on the Beehive-Middle Ridge.

I slid down the ridgeline between Truman and jones creek on Friday. Dug a quick pit where Alex likes to dig on the wnw aspect of the shoulder next to the main path. Melt/freeze at the ground about a foot thick, ten inches of loose facets on that, and a wind crust topping it 1-4 inches thick. And 5 inches of new snow. I skied the ridge down and the old drifts were supportable but intermittent. Eighteen inches of faceted snow in between that made for challenging skiing. It will be interesting to see what 2 inches of swe will do 

We rode to Ski Hill then around and up onto Lionhead Ridge. We found buried surface hoar in both locations,1-1.5' deep, with soft sugary facets below. Along the ridge we had two small, but audible collapses, when we walked from our sleds to a snowpit. We had ECTP23 breaking on the weak layer a little over 1 foot deep with HS of 84.

Skies were overcast to obscured with light snowfall. 1-2" fell through the day, and light to moderate winds.

Widespread cracking and collapsing at Tele Meadows today, primarily in wind-affected areas. Shooting cracks up to 100 feet.

S1 all day, only about 5cm new by 3pm. Winds mod in the AM, light in the PM from the south.

Still pretty thin cover, lots of sagebrush sticking through on the usual ski runs.

Headed into Blackmore Basin today planning to keep it low angle and to see the effects of recent snow and wind. Moderate winds with strong gusts were transporting snow the entire day, and a stout windslab was widespread. All previous tracks on the main SE facing run were completely filled in. Asides from the wind transport and some small natural cornice drops I noticed no other major signs of instability, but still kept a solid margin from avalanche terrain.

Despite a couple of recent observations stating that Bacon Rind could use more snow, we decided to try it. Perhaps we should have listened. Total snow depths ranged from 15 to 24" (39-61 cm in our snowpits), or in shorthand... not enough snow!

We toured up to the top of the Skillet in the northern of the two primary Bacon Rind areas. The thin snowpack was primarily comprised of weak, sugary facets with a thin soft slab (Fist to 4 Finger hardness) on top. In 2/3 of the upper elevation snowpits, there was a layer of feathery surface hoar buried on top of the facets and below the soft slab. Snowpack tests generally indicated instability (ECTPV, ECTP3, ECTP11, and PST 20/100 end).

While we chose not to roll the dice, the slab was thin (7" thick maximum), and we observed indications (slab qualities) that an avalanche most likely would not break widely across a bowl. HOWEVER, similar to what Alex and I saw at Lionhead the day before, it won't take much new or wind-drifted snow to change the equation, driving the avalanche danger up and making avalanches large enough to bury or injure a skier or rider likely. 

For now, it seemed that barely buried logs, stumps, and rocks were the greatest hazard. Once it snows enough to change the skiing quality meaningfully, I will worry about recreating on terrain steeper than 30 degrees due to avalanches. 0.5" of SWE would drastically change the picture. 

We ski toured in Sheep Creek today, north of Cooke City.  Of note, a thin (4mm) rime crust was forming due to the high humidity/ quasi rain.  Remarkably the rime crust skied very well.  

No avalanche activity observed (low vis).  No collapsing nor cracking experienced.  Light winds and mild temps.

Snowpit attached from a 9000', due south aspect, 32 deg slope.  HS 70, ECTP24 at 26.   

Another snowpit 50' away, with the same elevation and aspect, and 33 deg steep, had a similar structure, but resulted in an ECTN28 on the same layer.

Toured up into the Blackmore area today and found a pretty interesting upper snowpack with everything below roughly 8500’ wet from yesterday’s green housing and up slope winds in the Hyalite area. From trailhead to our peak elevation at 9500’ the new snow from last night ranged from a dusting to about 3 inches and capped the wet snow. Above 9000’ winds were actively loading the snow and I got cracking and a very small slab to release on a small wind drifted roll over at 9500’ on a N aspect. Later in our tour we dropped a cornice on an E slope and there was no avalanche activity, albeit the snowpack below the cornice seemed to be very thin as the cornice pulled off most of the surface snow and exposed a lot of rock. Overall decent ski conditions above 8500’. 

Today, we toured up and out of the north boundary of Bridger Bowl: up the Ramp, into Wolverine Bowl and on top of Texas Meadows. We got eyes on a lot of terrain north of Bridger and were able to dig in six or more different locations, with up to 12 extended column tests. Generally, we found a similar snowpack here as we have seen in the rest of the Bridger range: a slab of varying depths but generally about a foot thick on top of 1-2 mm facets generally in the middle of the snowpack.

In our pits near the top of the ridge, we got unstable test results with propagation on top of the facets. But as we dropped elevation, we found that we were unable to replicate propagation, and only got ECTN scores. These pits at lower elvations looked very similar to what Ian and I found just north of this area on Thursday (Ob from the Throne). One notable pit finding was a very thin layer of surface hoar near the top of the Ramp, as noted in our snowpilot (attached). 

Pit propagation was our first sign of instability, and as we continued along ridge past Wolverine we came across a R2 D2 slide in the Hourglass chute above Wolverine. It looked to be triggered by an intentional cornice drop, was around 12 inches deep at the crown, 100' wide and ran 850' vertical feet. It looked around three days old. As we skied down into Wolverine from the Ramp, we noted two other avalanches that seemed like they broke during the loading event that occurred last Sunday/Monday (12/15-16). These slides looked similar to the natural avalanche noted on Saddle this Thursday (Saddle Peak avalanche observation). 

Throughout our tour, our snowpack layers looked very similar. Pit propagation up high and recent avalanche activity showed us that the odds of triggering an avalanche in steep, wind loaded terrain were higher than we were comfortable with riding today. At lower elevations, our findings indicated the odds of triggering an avalanche are becoming less likely.   

Surprisingly shallow snow pack on the upper parts of Bacon Rind.  South of Skillet area in the meadows.  2-3 foot depth max at 8800 on a SE aspect.  10+ inches of newer snow on top of a well developed surface hoar.  A semi-supportable crust below that with facets to the bottom.  ECTP 11 really surprised us, failing on the surface hoar.  Challenging skiing staying on top and did some base damage on rocks even up high.  Log jam roller coaster back down to the car. Still a fun outing.  Send us snow!  And keep up the good work!

We rode up Denny Creek to the local's route. Coverage was thin, but passable as we left the Denny and worked up through the trees. The trail hadn't been set in yet this season. We didn't go far once we arrived in the openings below the ridge because visibility was poor. No avalanches or red flags for instability observed (but poor visibility). 

The snowpack was weaker than everywhere else Alex and I have been this year. The snowpack remains thin (60-80 cm). The post-Thanksgiving dry spell resulted in a well-defined layer of surface hoar and near surface facets. Below that the base of the snowpack transitioned to large grain sugary facets and depth hoar. Resting on all this weak snow was a cohesive slab. In the non-wind-loaded terrain where we rode, the snowpack seemed to have adjusted to the current load (ECTNs in the high teens to 20s, PST 30/100 arrest). However, new or wind-drifted snow would upset this delicate balance. We avoided wind-loaded terrain where avalanches would be most likely, though this was partially because our planned route simply didn't intersect with commonly wind-loaded slopes. 

While snowpack tests were not propagating failure today, just a few inches of snow (over 0.3" SWE) would change the picture. The danger would increase and collapsing and human-triggered avalanches would become likely. 

On the drive we saw one small wind slab in Yellowstone that looked 1-3 days old (photo attached).

Visibility improved on the drive back, with high clouds, and we looked towards Lionhead with Binoculars from the highway and did not see any avalanches.

Snow surface soft with ~3" of new, mod-strong SW winds at 11am 

Reactive tests in snowpits with low to moderate ECTP scores.  HS 105, NE aspects at 9480'.  

Experienced collapsing on the north end of Rob's, likely failing on buried surface hoar that was evident in pit.  

ECTP 15 75cm up from ground. HS90-110 9000ft SE aspect. Down 1000 feet similar aspect we also got propagation up 23cm with a HS of 55cm. Photo from the 9000ft pit.

Small slide in terrain trap. Looks to be old, likely from before the wind event that occurred mid last week. A snowmobile track leads into it with wind-drifted snow covering the track.

From email: "Rode buck today.  It was very windy this week.  Open areas are quite scoured, but there are still great stashes to be found if you hunt around.  We triggered a 12" soft wind slab on a NE facing slope at 9,5k'." 

We got into the Maid basin around 9:30 am while things were still cold. Much evidence of the recent wind event in the alpine with widespread wind slabs ranging in thickness from an inch to feet. There was some natural avalanche activity on the peak south of mt Bole. 
 

Got an ECTN 19 and 23 on a SE aspect at 9300’ HS 95cm

This was on a thin layer of facets sitting under a crust at 58cm. With a few prior hand pits showing planar shear on this layer we opted to keep it low angle.

By noon things were getting quite warm and Skiing through the thinly covered, glopy bushwhack back to the trail was our crux for the day. 

Snow rangers went as far as 3rd Yellowmule. We saw no new snow but evidence of wind effect, including a sizable, probable windslab avalanche Top of Macattee Basin