Snow Observations List

skinned up to the ridge and observed 5-9 inches of new and accumulating snow forming into wind drifts that were highly reactive. Multiple remote triggers occurred while traveling N on the ridge, propagating  both on W and E faces of the ridge. Both Hidden and Northwest Passage slid with little effort down to an icy bed surface. Debris at bottom of hidden was substantial but great skiing. 

Pics below of a natural wet slide that came out of Close Call yesterday afternoon (4/11/23), debris ran to the bottom of moonshine.

From 4/11/23: Yesterday (4/10) Colters released a wet slide (approx 1-3pm) that filled the top of the wiggle and left debris 300ft past the south bowl traverse.

Today Stupor had a similar sized release just after noon.

The best noted natural release was a wet slab release on the southern edge of the football field that put a pile of debris below the cave.

Although I only photographed North Bowl slides that ran very far, most of the chutes showed signs of wet slides running from the ridge. These were both in the bowl next to PK and north bowl.

From Big Sky Ski Patrol: "Temps remained a little cooler than yesterday and generally topped out in the mid 40’s F. That didn’t stop the free water from moving
and continuing to destabilize the snowpack, primarily on solar aspects below 10,000’. Near full depth to full depth wet loose avalanches continued to naturally release in what was left of the A-Z’s as well as LRT which had not seen any activity yesterday."

We rode up to Lulu pass, around the back of Fisher Mtn, behind Crown Butte and out Miller Creek south of Crown Butte/Daisy Pass. The upper snowpack was wet, but supportable. We dug down about 3 feet in a meadow in Miller Creek. HS 255cm. The snowpack was wet in the top 20 cm. -1.5degree C down 20cm and -3C down 60 cm. Still dry 40 cm below surface.

Wind was strong out of the southwest. Skies became mostly cloudy around midday, but seemed to clear slightly in the afternoon. Temperatures in the high 30s to mid-40sF.

There were maybe 6-10 D1.5-D2 wet loose slides scattered around the area that we could see, similar to attached picture of Crown Butte (We could see Miller Mtn. east and north, Scotch Bonnet, Henderson, Crown Butte, Abundance, Wolverine). At lower elevations where the snowpack is shallower, closer to silver gate and the northeast corner of the park, there were some deeper wet loose slides (D2) and a couple small wet slabs (photo). I would estimate most of these happened yesterday (4/10). Today, a D1.5 wet slide buried one lane of road in YNP on a steep, treed ENE facing slope at 6900'.

From IG: “Couple shots from today In the cooke area.”

Drove Bridger Canyon to Seitz road around 5pm on 4/10. Saw 4-5 D2 wet loose, plus many D1 wet loose. No huge slides or widespread large wet activity, yet.

From email: "This afternoon en route back to Livingston from Idaho, lots of slide activity at all elevations…

The first picture is the cornice collapse. One block in the debris pile was probably the size of my airplane - a giant ass snowball. 

The next few photos are wet slab a mile north along the same ridge, location: approximately 1-2 miles SW of the coordinate photo (it took me a minute to get cords up). Elevation of both approximately 9,800-10,000. 

Too many point releases to count in every range I’ve crossed today…"

While descending from a trail “run” (definitely more of a post hole) up towards Baldy, I saw a medium-sized wet slide on the eastern side of the ridge underneath some large rocks. The slide was roughly 15-20’ across at the portion I could see and traveled several hundred feet down the mountain. I could hear trees snapping (sadly in the video I don’t think you can, as my breathing is way too loud) and watched the avalanche move for almost a minute. I was very thankful for my careful route finding and avoidance of steep slopes! 

~ (45.7311237, -110.9639991)

Big Unit of a avalanche, photo taken from the Seitz road.

Today we observed wet loose avalanche activity on the southerly aspects in the mountains around Pioneer mountain. We also observed one dry slab avalanche on a NE aspect of Sphinx mountain at approximately 9,000’. 

We toured in Hyalite today. By 10:30 in the morning we saw wet, natural avalanches coming down east facing cliffs. We also saw several pinwheels from yesterday. By noon we were at 9,900' on a SE facing aspect, and the snow surface was wet at this altitude. Once we were down at 9,000' the top 8" of snow was wet, and it was beginning to move as a slab on small rollovers.

We skied three runs south of Quake Lake, up to 9400 ft. Most snow was crusty until it warmed up, but we found some powder in the shade and on north and east aspects, especially up high.  Dug a pit at 8400 ft, N aspect, 32-degree slope.  Result was ECTN-20 at 25 cm, and ECTN-22 at 35 cm.  Sheared fairly cleanly.  We were halfway up the avalanche chute at that point, so skied down with no incidents and skied two other tree runs.

We toured into Emigrants southeast bowl on Saturday. We found thin and reactive wind slabs on north facing slopes. Our ECT on a north face gave us stable results below the wind slab layer. It was the second day in a row of high temperatures and full sun but there was very little wet slide activity in this zone. We observed multiple old crowns in the surrounding mountains that looked to be a few feet thick. They were possibly breaking on a crust layer we found about 2 feet deep in our pit. 

Documenting local avalanche cycles, attached is a photo of an avalanche on the south face of Mt. Abundance taken yesterday, that likely happened last Sunday (?) when we got 1" of SWE overnight.  Lots of debris chunks the size of refrigerators.  Crown mostly covered by wind blown snow.

We toured out to republic pass. Saw mutliple small natural wind slab releases. We dug a pit on Republic Pass around 9800 ft on a north facing slope with lots of wind, got an ECTP 26 @ 30cm down from the snow surface on a very thin layer of facets. We only dug a ~5ft deep pit but found very stiff and solid snow throughout the snow pit (1 finger to pencil stiffness). Very little fresh snow was on the surface due to the wind ripping through the pass. It snowed for the whole first half of the day, lots of wind but only about 1cm of accumulation.

Lots of naturals and maybe a rider triggered avalanche seen today. Steep solar aspects had lots of wet loose activity and small cornice/pillow fall. 

Went for a ski on Jumbo Mountain via the Lava lake parking lot....

The big surprises for the day were 3 separate deep slab avalanches since the most recent loading event (likely 4/3). Photos are attached. The first that we sighted was on the N/NE face of Jumbo. It appears to be cornice fall triggering a windslab that stepped down, photo attached. 

HS-N-R2-D2-O @ around 10000ft on the N/NE face of Jumbo.

the next that we sighted was a large deep slab on the E face of the ridge just north of the true summit of Jumbo. 
 

HS-N-R2-D2.5-O @ around 10,000ft. 
 

The real show stopper was on the E face of Jumbo.

HS-N-R4-D3.5-O/G. Approximate crown width of 1000ft and average depth of 6-8ft. Total run of around 2000ft. A few photos attached. 
 

other slides of note, a few D1-1.5 WL slides low in the basin SW facing. Also, an older deep slab on N facing terrain just south of Hell Roaring Lake, D2-D2.5.