Snow Observations List

When setting out to Beehive Basin today we only imagined wanting to bail if rain line was at the trailhead, but had not expected our seasons long standing PWL to turn us around. With a few inches of snow at the trailhead and temps just at freezing we set out. The new snow yesterday/last night capped a warm snowpack, keeping the snowpack from freezing at all (no crusts or other signs of superficial freezes up to 9,2000ft where we bailed despite the mid-20’s temps recorded overnight). Almost immediately out of the trailhead we got thunderous collapses so big we at first thought it was noise from control work at Big Sky. Further along we got collapses extending hundreds of feet out, valley wide and echoing up the basin. We dug to the bottom out of curiosity and found a saturated and unfrozen snowpack. The bottom 30cm was still all facets, giving the appearance that the remaining 90-110cm of consolidated snowpack was floating on air. We’re assuming the whumps/collapses are traveling along this layer of basal facets. I’m sure once it gets a solid freeze things will be alright again, but will the new snow continue to insulate the snowpack the next few nights despite the forecasted solid freezing temps? Or is this only a phenomenon that happens the 1st night of new snow falling on a warm snowpack? 

Came across a relatively large wet avalanche when approaching Texas meadows from Bradley’s meadows. Elevation around 7600ft, aspect, SSE. Depth: to ground. 

Considering the new snow on top of the debris, I’m guessing this slid prior to the storm last week. The slide path was melted out to dirt. Out of curiosity, we dug just to the lookers right of the slide and found soft snow near the ground - still evidence of crystal structure but could make a snowball if squeezed. Best guess is that a point release wet slide entrained enough snow to step down and release the whole face. 

Elevation: 10231

aspect: ESE

time: 10:35, April 22nd 

CTX - broke below isolated block, pit depth ~100cm 

Avalanches in the goose lake area: small loose snow avalanches on shady aspects. Evidence of rollerballs and small cornice falls on sunny aspects from previous days. 

Toured up around bell lake today and after a night of wind, triggered a very small wind slab in a north facing couloir at around 9500-10000ft. It was almost 10” deep and was about 10-15ft across. Snow was being loaded through out the day and was staying cold up high. 

Dug a pit around 9700' on a WNW shaded aspect below a couloir on Miller Mountain in Cooke City. We found ~95cm snowpack, with 5-10" of lower-density fresh snow. We dug to the ground and found a consistent and firm snowpack all the way down, didn't find any facets at the ground. Isolated cracking, ECTN25 ~20-25cm down, below the thick melt-freeze crust from the warm-up immediately before this week's snow. The fresh snow had sluffed out on most chutes before we got there (likely during the storm) but we saw very little sluff triggered by our skiing

The fresh snow skied great on shaded aspects that hadn't been affected by wind. Non-shaded snow surfaces were definitely getting wet by 1 pm, the sun felt hot, but we didn't observe any wet slides before we left. The snow on the ride out was very wet, with watery-slush puddles on the lower parts of the trail.

Cookes' always interesting in the spring, deep slab goes to sleep and the Grizzlies wake up. Curious how she knew to thread the cornice just right(Sheep Mt). Second Pic is a large sluff on the Fin, couldn't quite make out the track route till I drove to Silver Gate. He skied the hanging gully to the east of the third pic and rock climbed across the cliff to this sluff and tracks... Don't ask how I know it was a grizz, no time to get a pic.

We saw several loose avalanches on WSW, ESE & SSE aspects of the ridge between beehive and bear basin.  The one on the ESE slope may have been skier triggered (by another group) and the rest appeared to be natural.  We found a strong crust beneath the foot of new snow throughout our route.  We didn't see any cracks or whumphs, and the new snow wasn't reactive in hand pits.  The snow surface was getting wet as we exited to the beehive trailhead around 3pm.

Out in the Western Tobacco Roots today. Recent snow was decently wind affected and storm depths were particularly variable. One thing was common with all new snow deposits: they were bonded very poorly to the widespread underlying crust. In most areas the new snow was not cohesive or deep, so this resulted only in tricky skinning and long running sluffs.

However, where wind or sun had strengthened the slab this surface layer was reactive, with sluffs entraining significant amounts of snow and one small slab that I managed to trigger. I popped this slab underneath a mild, somewhat cross-loaded convexity on a north face near treeline, and it broke around 30 feet wide, 4-6 inches deep, and ran ~ 300 feet (N, 9500', SS- ASu - R1/D1).

The underlying snowpack showed no signs of instability, though while boot packing I did break through the crust in some shallower areas and found some basal facets. The snow surface stayed pretty cool throughout the day above 8.5 kft, and winds were light out of the west.

Skied the Banana Coulior off Ross today. 6-8" of fresh, dry snow has fallen and lies above a bomber crust that was observed on all aspects we traveled on. The weak interface between new, dry snow and the pervasive crust allowed for a large sluff, or dry-loose slide, that began near the top of the Banana Coulior and ran for ~ 500'

From IG message 4/17/24: "Remote trigger up little bear today. Went to the groundish."

Wet slab 150-200 ft across, SE shoulder of Abundance towards Wolverine. Looks to have maybe happened before new snow. New snow 6-8 was extra funky, 2-3 powder on a rain? crust on heavy wet. Bonded to unsupportive melt freeze on completely saturated glop. Lots of short running sluffs

From IG: A group of riders noted very wet snow west of Cabin Creek and Southwest of the Taylor Fork. They were sinking to the ground where it was unconsolidated. The group remotely triggered a wet slab avalanche from the ridge top. There were shooting cracks that connected their location to the avalanche. This is an interesting of persistent weak layer and wet snow avalanche problems. 

From IG: Wet slide to the ground above Quake Lake. 

On sunday 4/14 a large wet loose avalanche ran naturally in closed terrain at Bridger. The larger of the two in the photo is from 4/14 at 1230pm. The other slide, on the left, happened yesterday or late in the day Friday.

Saw what looked like a wet slab avalanche from the road along the Madison River.  Roughly north facing slope at 7500'.

Saw a slab avalanche on a NE face at around 9000-10000 feet. Did not see any signs of instability on the tour, but there was not a very concrete freeze. Everything below 8000 remained unfrozen. 

This afternoon I drove up Bridger canyon to Seitz Rd to see the extent of wet snow activity, and stopped in a few places to look with binoculars. There were many loose wet avalanches that ran over the last 1-3 days. I estimate they involved the upper 6-12" of snow. Activity was widespread and many slides were plenty large enough to be dangerous, but there was nothing especially remarkable about the size and I saw zero wet slabs.

Temperature was 65-70 degrees in the canyon, mostly clear skies with a few clouds, calm to light wind.

Natural cornice failure and small slab on Iceberg Peak’s NE face. We skied by the day prior and judging by what the wind did to our tracks overnight, this looked like it happened in the morning.

Rode from Buttermilk to Lionhead Ridge to take down the weather station for the season. The snowpack was fully saturated and sloppy at lower elevations. By 8000 ft there was a firm crust with a couple inches of wet snow above it around noon. Winds were breezy at ridgetops, keeping the snowpack a bit cooler (but still getting wet). Ominous clouds moved in around 12:30 pm. We quickly left before getting rained on. 

We saw no signs of recent avalanches.

Rode up cottonwood creek on the west side of the crazies. Saw several recent wet loose slides on southern aspects as well as some isolated slides on north/west aspects. Only saw one larger slide that had a wide crown(500ft) D2 on an east aspect.  All slides were breaking in the upper 40cm in new/old snow.

Dug a pit north east aspect HS270cm ECTN24 @40cm down from surface. Melt freeze down 70cm might start reacting when water penetrates through upper snow pack, dry snow in upper 60cm but becoming more moist on solars.