Northern Gallatin

From obs: "Skied Mt Blackmore this morning. Very windy up in the basin, but calm along the ridgeline. Lots of signs of wind-loading and drifting on most slopes. I felt/heard 3 collapses while ascending the trees up to the east ridge. Saw a debris pile on the N face, likely from a cornice fall in the last 24hrs." Photo: M. Lavery

Skied Mt Blackmore this morning. Very windy up in the basin, but calm along the ridgeline. Lots of signs of wind-loading and drifting on most slopes.

I felt/heard 3 collapses while ascending the trees up to the east ridge. Saw a debris pile on the N face, likely from a cornice fall in the last 24hrs. Stayed low angle in the trees on the way down, and triggered a few 1-2" thick wind slabs on isolated features while skiing out of the basin.

This morning I was ascending Flanders Peak via the southeast trees. At approximately 10:30AM, 9500 feet elevation, we dug a pit (photo attached) and was surprised to get a ECTN. However, we did make notes of a buried solar crust between 51-60cm (1F) and a basal crust (P) on the first 5cm of the pit with the same large, sugary facets we've seen all over the Bozeman area sandwiched in between these two layers that supported our plan to stick to low angle slopes. At approximately 1:30PM, on our second lap of the south-southeast bowl of Flanders Peak, I was skinning behind my friend who was putting in a new ascent track when we both heard a large "whump" and a 15 foot crack shot out from under his skis. I also witnessed him drop several inches from the large collapse in the snow. We were on a very low angle slope (less than 25 degrees) at approximately 9700 feet, in wide open trees right at the edge of tree-line and the alpine. We noticed no other signs of instability in the bowl we skied, or on the wind-loaded ridge. We decided to not keep lapping the bowl after this happened but instead skied back to the car.

I toured up to divide today and ascended the lower east shoulder of divide pk
There were no obvious signs of instability so I ascended the Low angle terrain to the north east of the pk
I dug 2 pits on my ascent one propagated at the ectp17 and the other at ectp25
From these results I keep off any of the small roll overs or steeper pitches of that east flank of the pk and just road the 30 deg terrain to far lookers right of the pk
I was up there two weeks ago And would not ski due to instabilities but the stability is improving but still can not be trusted

Yesterday I saw two tracks center punching directly off divide pk
I feel that person was totally rolling the dice

I did not ascent any slopes that were connected to steep terrain and keep the angle at 30 deg
The snowpack in hyalite can not be Trusted

Hi guys,

Toured out towards Hyalite Peak today and skied the open slope that is below Divide Peak, just across the creek from the summer trail.

Snowpack resembled everywhere else - weak facets under a 4F/4F+ slab and some soft new snow. In our pit, we got a CT20 and ECTN22 that broke on the basal facets but did not propagate (slab broke apart). We dug 2 more quick pits looking for a harder slab as we moved higher on the slope but the snow structure felt the same. Had one isolated whump on what was likely a wind loaded terrain feature, but otherwise no signs of instability. Stayed off the steepest parts of the slope and the skiing was excellent.

Mike

Went for a quick tour up Goose Creek this AM. Looks like a few inches of snow out of the most recent cycle on top of a very weak base (shocking). No more than 10-12in coverage up top. Clear skies, no wind, temp ~30F.

No evidence of wind loading or any slab formation. Just enough snow to navigate without damaging your skis and get a few turns up high.

90 cm snow depth on E/NE aspect. Extended column test propagated at 40cm from the ground, ECT 10.
We dug around 9000 feet elevation.

Approx. 50 cm snow depth on north/ northwest facing slopes, around 8600 feet.

I skied up Flanders today, and found conditions that are quite similar to my last visit a few days ago. A pit on an east aspect at 9100’ had HS 105 and gave ECTP15 just below a mid-pack crust that sits on ~25 cm of 4F angular facets. I did not experience any collapsing or cracking, and observed no recent activity. Despite the lack of obvious activity, the thought of skiing exposed terrain seems unpalatable to me.

This pit was 100-150’ below the one I dug on 12/28, and I did not find the well-defined pair of crusts that was present in that pit. I suspect being near some trees affected my results a few days ago. Nevertheless, the stability was poor in both pits, and the problem is the same—sugary, loose facets that cannot support much weight.