Snow Observations List

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. 

Skied Hyalite Peak today and found a wind slab ~10cm deep. Ski cut a small cornice below the main face and broke a small slide that carried ~20’ with little energy with a ~25’ wide crown

While on a tour today out in Republic Creek, we decided to skin a forested W aspect to gain woody ridge. As we started to near the alpine, we dug a pit on a N aspect at 9900ft and in return got a ectp24 at 30cm in our test. Snowpack in the area was roughly 110cm. The snowpack failed on a buried crust layer that has not bonded to the new snowfall.

~72 cm depth

ECTN13 @ 45cm

ECTP17 @ 30cm 

Location:

East Aspect

45.32868, -111.38167

12T 0470091E 5019534N

9311 ft

Essentially the same results as were shared in the forecast this morning.

ECTX on our snow pit on a shaded, west-facing aspect but sun has created a thin crust as well as some pretty large facets on the surface. Looked like wind had collapsed most of them but could cause problems after next storm

Looks like this could be a problem when buried.

We toured up to the Ramp through Bridger Bowl this morning. This week's winds hammered the snow at mid-elevations (from the bottom of the Alpine/ Powder Park Lifts to the top of Bradley's Meadow). Some areas were scoured to near the ground, with pencil-hard wind drifts in others. The winds hadn't affected the snow from the bottom of the ramp to the ridge as much. We dug a pit on the Ramp halfway up. There was 90cm of snow on the ground in the pit. The bottom 38cm is faceting into sugary grains, but they aren't remarkable yet. ECTN23 at the top of the facet layer at 38cm from the bottom. My primary concerns were thin snow cover and slopes with wind drifts from the past few days. Calm up there today. 

There are many barely covered rocks on the Ramp. There was a lot of skier and boarder traffic all over the mountain. Cars were parked in the F lot when we left. 

Strong temperature inversion in the AM, -4F in the meadow and about 20F at the ridgeline. Sunny by late morning with light winds. The southern aspects were getting baked pretty good in the sun. We were getting roller balls and snow globbing on our skis on the SE aspect to the south of the standard skin track. 

About 60 cm of snow at the top. Soft (F hardness snow) basically to ground. Almost no wind loading. Definitely can see some of the snow at the very bottom starting to facet a bit. We saw A LOT of surface hoar mid slope and down in the meadow, but very little toward the top. The northerly aspects had no obvious signs of instability yet. I'd expect the surface hoar and/or an extended period of dry weather could set up some interesting weak layers over the coming days/weeks depending on how the weather plays out.

Some fresh bear tracks on the skintrack into Sheep Creek a few weekends back. Funny to share a route with the wildlife. They're still out and about, make sure to carry your bear spray for a few more weeks!

I attached a few photos of a small wind slab avalanche (R1 D1)  from yesterday at approximately 7800 feet on the northern end of bradleys meadow. 

The slide was initiated by the second skier and although the rest of the slope was <30 degrees the starting zone was a NE facing steep cross loaded wind pillow just below the ridge. 

As my friend was skiing down he saw a crack propagate up and to his left and was able to stop on the side of the path as the snow ran past him. The  crown was approximately 30-40 feet and ran about 100 feet. 

Here are the coordinates of  a way point I dropped just above the top of the slide : 

45° 50.0218′ N, 110° 55.7420′ W

 we circled back and took a photo of the top as well...  let me know if you need anything else! thanks! 

We were at the ridge of middle basin @9400 feet. Before skiing we dug a pit and weren’t thrilled with the results. CT broke on the barrier between the fresh snow and the first dump that the area had. We got an ECTP 17 that went all the way across at the same old snow- new snow barrier @ 35- 40 cm from the ground. Stuck to the lower angle terrain and had a great day.

Me and my buddy went on a tour today up Sheep Creek to check out the new snowfall and conditions in the area. We dug a pit on a S\SE aspect at 9500 feet and found about 100cm snowpack. Last weeks snowfall fell right side up and was not able to find layers until the bottom 6 inches of the snowpack. About 6 inches from dirt, there is a minor crust layer with small facets under the crust. We did not find the new snow to be reactive to this layer during our column test...

Around 2ft down in the pit that was dug there is a generally stable storm slab but it still broke after 5 elbow strikes. Finger tip strikes did trigger a 3-4 in wind slab in the pit and a remotely triggered wind slab was observed halfway up the whiteworm. 40 wide and 5 in deep it ran for about 60 yd.

A skier remotely triggered an avalanche on Mt Blackmore (11/9/22).

From email: "I ski cut the top of the face and remote triggered a hard slab from 50’ above the crown. It broke full width of the couloir feature, 150’ wide and 10-18” deep. Broke on new snow/old snow interface which was another hard wind slab. The avalanche ran the length of the East face and stopped just below the last set of cliffs."

The pit depth was approx 80cm to the ground. Slope angle 19 Degrees. Air Temp 19* F. E/NE facing slope. Hardness Test/ Fist @ 64 cm, 4F @ 45 cm, 1F @ 35 cm, 4F @ 20 cm. Conducted CT (30cm x 30 cm column), Propagated at 25 (10 wrist, 10 elbow, 5 shoulder) propagation was just below the distinct layer that you can see at 35cm in the photo labeled BM5. Then conducted ECT (90 cm X 30cm) No propagation after 30 ( 10,10,10). Picture labeled BM4 is the layer that propagated on the column test.

Small slab avalanche triggered by skier in a small chute near The John and Bronco runs in Bridger Bowl. Propagation from skier’s ski, slab slid down through the chute. Crown maybe 10 feet wide. Slab looked about 6 or 7 inches thick. Looked like a layer of new snow from today and yesterday’s storm sliding on top of an old crust layer. Nobody harmed, just spooked. Watch out!

Our group of 3 skinned into beehive basin in search of fresh snow and expecting instability. We expected the bottom old snow to be likely decomposing and facted, as well as an interface between the wind affected snow and new storm snow. We dug a pit on an E facing slope 1/4 mile south of the lake, just past where the creek concavity eases. The slope we used for our pit was 23° and we found 80 cm of snow. See SNOWPILOT data for the complete snowpack. Our pit findings were drastically more positive than what we anticipated. The snowpack showed signs of being right-side up and having low slab formation within the new snow as well as weak layers that weren't very reactive. These findings provided us with more confidence in the early season snow than we had expected. As we moved south from our pit to a less wind sheltered area we found the upper 40 cm of the snowpack to be firmer than what was encountered from our pit. While ascending we used our poles to question this change and discuss how it would affect our planned objective. We still felt confident in our plan, but made note of a wind-skin on the surface to the south of us that we wanted to avoid. We got 4 laps on an East facing 35°-38° slope accompanied by 30 of our closest friends before skinning out with no instability observations on the slope we skied. There were however obvious point releases within and slightly buried under the new snow on adjacent west and southwest slopes further south down the basin. The west side appeared thinner with less coverage and more wind rippling as observed from afar. 

Today I got reassuring results from a snow pit dug at 9195' on a Northeast aspect (40 degrees) in the basin between Mt. Blackmore and Elephant Peak. The area was clearly wind-loaded with an HS of 110cm. I got a CT20, Q2 @ 50cm (see image), a resistant planar failure that appeared to occur on a thin layer of decomposing fragments. In my ECT, I received no results whatsoever, so I sense that this weak layer is quite unlikely to react, though structurally the snow consisted of a hard wind slab on top of an identifiable weak layer.

I also performed an analysis and multiple ECTs on a snow wall closer to Elephant Mountain (8950'), which was a Northwestern aspect (318 degrees). The snow wasn't as deep at this location (HS 73cm), and my results were ECTN22 @ 42cm, then ECTN21 @ 44cm (see images).

I hope these results are helpful as we begin to wrap our heads around this early season snowpack.

Thanks,

Charlie

Saw some cracking and propagation of a 6-8" storm slab on steeper terrain near the Bridger Lift. Gentle upslope winds seem to have compacted a slab near some terrain features, and I got a small propagation at the edge of the Sluice Box gully where the slope angle tipped up near 40.