Snow Observations List

I did some digging around on the Ramp this morning. Got propagating test scores with moderate force in 3 snowpits. Pit from just below the ridgeline on an East aspect at 8500' had a snow height of 120cm: ECTP16 down 60cm, interface between 4f facets and larger fist facets. A thin, soft 1cm MF crust was present down 15cm. I dug at 8000' on a South aspect, height of snow was 60cm, ECTP11 down 30cm below a 20cm MF crust, wet depth hoar to the ground. I also dug on a SE aspect at 8200', height of snow was 65cm ECTP13 down 40cm on dry depth hoar below a 15cm MF crust.

Except the top 200', a stout MF crust was near widespread below the new snow. Tracks in steeper terrain showed small loose dry slides contained to the new snow. It was warm, southerly aspects were getting wet by mid day, wind was light, I didn't observe any evidence of transport. 

Thanks for all your hard work!

Spencer

Toured up near fairy lake today. Several natural avalanches on Pomp, Sac, and Naya Nuki. Numerous whumphs traveling through the meadows. Did a quick pit on an eastern aspect at 8000'. HS110cm. ECTN8 at the melt freeze crust 95cm and ECTP21 at 65cm on some 1-2mm facets. By about 10:30AM winds were picking up and we boogied out of there.

From FB:

No avalanches observed. A foot of new snow in 24hrs, 3-4 inches throughout the day. Strong wind gusts in the morning into early afternoon, drifting in open areas and higher elevations. Experienced multiple whoomphing in an open flat area.

Gabe Gassman and I rode buck ridge to the wilderness boundary at Macatee basin on a LE patrol mission. 6-8 inches of new snow fell since yesterday. Snow depth was variable as it had been affected by wind, but wind during the day was calm to 10mph. No avalanching of the new snow was observed.

Skied conservatively terrain below 30 degrees today. Widespread whomping. Along the steeper part of the  uptrack, we experienced settling and shooting cracks.

We agreed that in steeper terrain this would have led to an avalanche. 

Four of us (all with 20-40 years backcountry experience) skied the lower angle slopes just south of the skillet at Bacon Rind. There was a well worn skin track from past weeks and lots of old down-tracks buried beneath ~8-10" of new snow. We heard numerous large-scale collapses and witnessed the development of propagating tensile fractures on a 20°-25° slope along the skin track (see photo/video). No need to dig a pit on days like this. We did not venture onto or view any steeper terrain, so we saw no natural avalanches.  The new snow seems well-adhered to the older snowpack. All instability is tied to the lowest 20-30cm faceted sequence at the bottom. 

We skied this location 4 times this week. Each time, we experienced collapsing and fracturing within the snowpack and stuck to skiing conservative, low-angle lines. The takeaway? Previous skier traffic may not indicate safety or diminish avalanche danger. If conditions are even somewhat questionable, stick to low-angle slopes or go nordic skiing (on groomed trails). 

Observed a fresh avalanche this afternoon on Woody Ridge, South of the Submarine. Northwest facing slope, Approximately 10,150'. Appeared to be from today, 2/4. 

Multiple natural avalanches and at least one suspected human triggered dry loose in Beehive Basin. Most naturals appeared to have run either last night or yesterday (2/3/24), with a couple potentially older slides. New snow and rapidly changing cloud cover/depth perception made it a bit hard to be sure. Suspect one skier trigged dry loose in W facing trees. One of the W-facing chutes further up valley was also observed to have a crown line at approximately 9000' (no photo)

Main points of test profile to ground at N45°31.5026' W110°57.3867'

• Foot pen all the way to ground with very weak layer at base. 
• Some rounding at the mid snowpack (15cm down to 50cm) with ~P resistance. 
• MFcr interface layer @ 20cms
• CT Result
  • CTM 14(SP) down 50cm
• ECT Result
  • ECTN7 down 15cm
  • ECTP27 down 50cm

On the terrain travelled, NE - SE slopes have ~70-80cm coverage. W slopes have very thin cover and presented minimal avalanche risk. 

We rode north of Cooke City today, 02/04/2024. We stopped below Fisher Bench and dug on an NE-facing slope at 9600'. What we found were unstable test scores, ECTP25, and a poor structure of weak snow. This pit had a well-defined strip of surface hoar that stability tests were failing on. 

We moved on from here over Lulu Pass and towards the wilderness boundary. Along the way, we saw multiple old avalanches and a few more recent ones from last week's warm-up. While climbing a small test slope I saw shooting cracks coming from my skis, and could feel my track breaking through the slab to the weak snow below. Overall the snowpack is in poor shape and just putting a foot down in some places it was easy to break through the slab and fall to your waist in facets. 

Light snow fell through the day will little daytime accumulation. The storm was well distributed with 3-4" in all the areas we rode today. Winds were calm and the sun tried to break through the clouds but it remained mostly cloudy. 

We dug a pit near the top of the skin track, and when approaching the location we experienced a big wumph. After digging our pit, we got a ECT3 on the more recently buried weak layer. 

Went snowmobiling/skiing below White Peak. We saw older crowns down low in the meadows. While skinning up a mellow south facing nose off white peak, we dug down and got a ECTP15 2.5 feet below the surface. About 8-10 inches of snow fell throughout the day up high. As we continued to skin up higher, we observed numerous collapses before we decided to call it a day. We observed that aspects without a crust layer from this week were more reactive, although we saw propagation on solar aspects with a defined crust as well. 

From email: "Temp 27. 4'' new snow, Rate S1, Sky OVC. NE aspect, SE winds, L  observed localized drifting. Elevation 7790’. conducted several CT tests scored CTM and CTH (SC)  ECTP 21, NE of Two Top on a layer of SH 35cm from surface. New snow on a melt freeze crust very reactive CTE 15cm from surface. Possible new layer of concern as new snow accumulates. No recent avalanches observed."

120 cm HS, OVC, E aspect, 6" new snow, -4c air temp, 14 deg. incline, blowing snow: none. ECTP 22 at 101 cm

Went up Lick Creek today with the intention of getting out in the new snow and doing some digging. We dug a couple pits on a north aspect at the top of the meadow at 8064' in an area of wind drifted snow. We observed propagation in both pits up 25cm on a faceted layer. HS 64cm, ECTP21, CT17 Q2. Skiing on the SE aspect was very thin but decent on a firm supportable crust formed during last week's warmer temps. 

North of sawtelle peak between sawtelle and Bootjack. General observations of surprisingly low snowpack. Traveled from red rock parking lot to flats to Bootjack then south toward sawtelle then east to the flats and back north to red rock parking. The northern area had on average 6-10 inches, the southern area had 12-15 inches. Elevations were between 6300 and 7200 feet. Aspects were mostly NW to N to NE to E.

After riding around in Miller zone rode up towards the east Crown Butte avalanche from this week to take a look!

Dug near the old cabin structure HS 100cm -140cm  in area

210  deg aspect, @ 9380 ' on a 10deg slope

HS 110cm, ECTP28 on 3-4mm facets 20 cm up from ground. 

Notes: solars and low elevation slopes formed a thin breakable crust over the last three days, under the crust in many places is a thin layer of faceting snow on top of a hard slab. 

From email on 2/2/24:  "We received a call of a missing snowmobile in the Keg Springs area of Island Park at 1642.  The missing snowmobiler arrived at 1800 hours at the rental property his party is staying at and said he had self-extricated from an avalanche."

I drove up Bridger canyon this afternoon and stopped in a few spots to glass the range for recent avalanches. There were many recent wet avalanches, both wet loose that gouged through the snowpack and wet slabs about one foot deep and 50-100' wide. Many size D2, some smaller. Happened sometime between Monday and today (1-3 days old, maybe some this morning). The main spots for recent wet avalanches were on Bridger Peak and south of the Throne. Mainly on sustained steep terrain with rocky outcrops and east-south facing. There was one wet slab on a northeast facing, mid-elevation slope near the Throne. South facing terrain near Fairy Lake had some wet loose activity. I attached a photo of the wet slab activity on Bridger Peak and south of the Throne.

I also saw a wide crown in Frazier Basin and a similarly wide crown in another bowl to the north (300-400' wide). Photos attached. I am not sure if these occurred recently with the above freezing temperatures or if they are older. they do not appear wet like the others, but I could not see the debris and was generally far away. Also they are in higher terrain favored for cooling effects. But, they easily could have occurred over the recent hot days, potentially triggered by cornice fall?