Northern Gallatin

I took a tour up Ellis today, and things haven’t changed since you guys were up there. A pit at 7400’ on the ascent had HS 105 and ECTP15 on depth hoar 20-30 cm off the ground. The surface conditions were excellent; subsurface not so much. I don’t imagine that will change very quickly. There was a light east wind on the ridgeline, but it wasn’t transporting much of anything.

On Thursday, Feb 11, snowmobilers remotely triggered two large avalanche in the Portal Creek area.

From obs: "Broke on lookers right crown first then triggered second slide to lookers left (rocks everywhere). Broke on depth hoar on both slides north facing aspects. Nobody was caught."

On Thursday, Feb 11, snowmobilers remotely triggered two large avalanche in the Portal Creek area.

From obs: "Broke on lookers right crown first then triggered second slide to lookers left (rocks everywhere). Broke on depth hoar on both slides north facing aspects. Nobody was caught."

On Thursday, Feb 11, snowmobilers remotely triggered two large avalanche in the Portal Creek area.

From obs: "Broke on lookers right crown first then triggered second slide to lookers left (rocks everywhere). Broke on depth hoar on both slides north facing aspects. Nobody was caught."

8,023ft elevation, SW aspect, 19° incline
STM ^25cm
CT13
ECTP12 (@ same 25cm point)
1.3° C temperature change per 10cm
total pit height = 75cm

From Obs 2/9/21: "Up/down the SE Ridge of Blackmore today. No cracking/collapsing observed. One large avalanche observed, on the path adjacent to the N Couloir on Alex Lowe. More or less went full path, I would estimate 2m max crown depth. HS-N-R4/D2.5-O. Observed several size 1 slabs that failed within new snow during the day on N aspects." Photo: S. Hennessey

A natural avalanche that failed on Cedar Mountain during the tail end of the storm. Photo: GNFAC