Northern Gallatin

From obs: "Hi Guys, Skied an open slope adjacent to Hyalite creek... Lots of natural sluffing occurring within the new snow. This particular slope has some steep cliffs above it, and point releases from the cliffs would entrain new snow and run 200 ft downhill. Have a picture attached showing 2 of them, but saw about 7 or 8 of these throughout the day. Activity picked up in the early afternoon when the snow picked back up." Photo: M. Lavery

There was about 6" of new snow in Flanders. It snowed on and off all morning and kicked in again around noon. There was no wind. We climbed Killer Pillar (E. facing, ~8600'). In about a 45 minute span we had 5-6 large sluffs barrel over the top of the climb and run a few hundred feet down the gully...a long ways. Luckily we were not climbing the gully or leading because it would have peeled us off. We descended to the north to stay out of the gut. We were in avalanche terrain and had the surface snow sluff far down the hill. It was running so fast and far I had to stop and dig a quick pit to see why. It was near-surface faceting under the snow. I had an ECTN. There was not enough of a slab to propagate a fracture. We made a quick movie which is posted on YouTube.

LS-N-R2-D1...could be R1...no way to know, but by the time they all ran I imagine a lot of the bowl above had released.

I was super psyched that we both had our lighweight shovels and probes and were beeping. You just never know!

Hi Guys,

Skied an open slope adjacent to Hyalite creek. Dug a snow pit at ~8000ft, E facing, 15 deg slope.

20cm of new low density snow. Surface hoar was buried 35cm from the surface under a 4F slab. Had a CT 2 on the new snow/old snow, and CT 18 BRK on the surface hoar. ECTN 2 and 17 on the same layers. Also did a cross slope PST in the surface hoar and had 95/100 end, but the overlying block broke apart when I pulled it into the pit. Facets at the ground were 4F- and unreactive. Had no cracking or collapsing. Skiing was some of the best of the year.

Lots of natural sluffing occurring within the new snow. This particular slope has some steep cliffs above it, and point releases from the cliffs would entrain new snow and run 200 ft downhill. Have a picture attached showing 2 of them, but saw about 7 or 8 of these throughout the day. Activity picked up in the early afternoon when the snow picked back up.

Toured up to blackmore and skied the low angle meadow below the east ridge. 6-8” of new snow that fell on a very firm bed surface. I did not dig a pit, but the firm layer under the new snow felt like a wind slab. The firm layer was less prevalent in protected areas.

Sorry about the old data but I though some Hyalite-specific observations might still be useful. We did a quick compression test near the base of Divide Peak on Saturday (location on map below should be pretty accurate). I could not see the buried surface hoar but maybe I should have looked more carefully because the compression test revealed two weak layers. We got: CT11, Q1 @ 12" below the surface, CT14, Q1 @ 15" below the surface, and the ground facets (about 36" below the surface) crumbled at CT22. More subjective observations: snow penetration while skinning was only about 6 inches and even hard turns only made 10"ish deep tracks. Nice snow, but relatively firm base.

Kind of a crap picture, but from the Dribbles today I noticed some natural activity on the SE face of Arden peak in the Maid Drainage, seemingly from cornice fall.

From Obs: "I skied into Maid of the Mist today, it looks like part of a cornice fell and it failed on a wind slab from last weekend’s snow. It did not step down to the depth hoar. Photo: S Reinsel

Dug a pit on a southwest facing slope at around 9500 feet. Found a top layer of new snow, few inches bonded ok. Main layer on facets 75 cm deep. ECTP26 took quite a bit of force to get it to release from the layer. Facets were harder than a couple weeks ago but still garbage snow on the ground. Numerous recent avalanches spotted in next drainage to the north. See pictures.

I skied into Maid of the Mist today, which is now pseudo-passable, for the adventurous. I got a better look at the avalanche I saw from Divide yesterday, and it looks like part of a cornice fell and it failed on an wind slab from last weekend’s snow. It did not step down to the depth hoar, which is encouraging.
We dug a pit at about 9600’ on a south aspect, and found 160 cm and got ECTX. I suspect other aspects would not give the same result, though, and am cautious to get very excited about this.