Regional Conditions for Northern Gallatin

"Observed two dry-loose slides and one slab avalanche on the NE-facing slope of Peak 10,024 in the Shower Creek basin on Sunday, 2/28 - all were presumably naturally triggered." Photo: K. Busby

"Observed an old crown line and covered avy debris on a NW-facing slope looking SE from Hyalite Lake." Likely occurred around 2/24/21. Photo: K. Busby

Wet loose avalanches released in the warm sunshine on Tuesday, March 2nd. We expect many more in the coming days. Photo: S. Jonas

Sled Skiing in Third Yellow mule... after an air onto the slope the impact from landing resulted in a fracture and failure to / near the ground... in addition, a remote trigger occurred on adjacent slope... 200-300 ft to the skiers right. No body was caught in either slide. Skier that initiated failure was moving at high speed and was beyond slide path before majority of snow movement began. Photo: W. Miller

Sled Skiing in Third Yellow mule... after an air onto the slope the impact from landing resulted in a fracture and failure to / near the ground... in addition, a remote trigger occurred on adjacent slope... 200-300 ft to the skiers right. No body was caught in either slide. Skier that initiated failure was moving at high speed and was beyond slide path before majority of snow movement began. Photo: W. Miller

Sled Skiing in Third Yellow mule... after an air onto the slope the impact from landing resulted in a fracture and failure to / near the ground... in addition, a remote trigger occurred on adjacent slope... 200-300 ft to the skiers right. No body was caught in either slide. Photo: W. Miller

This avalanche was triggered on Sunday, 2/28, when a skier released another slide 2-300 feet away. It broke at the same time. No one was caught. This was in the Third Yellow Mule on Buck Ridge.  Photo: W. Miller

Photo: C. Dokken

"Saw this crown the morning of 2/28 from G1 while climbing." Reported to GNFAC (earlier in the week). Probably slid last week during other large slides nearby. Photo: V. Beineke

"This was observed from the genesis area in hyalite. It was on the north east facing Bowl off elephant mountain about 800ft above the un named wall." Photo: B. Durrum

There was 6' of snow off the ridge in the Bridger Range on an east facing slope. The top 2 feet were recent wind drifting that broke clean in our stability test which indicated unstable conditions (ECTP18). We expect similar conditions and instability with wind-loaded slops throughout our forecast area. Photo: GNFAC

In the last 24 hours (2/28) 12" of low density powder and 40-50 mph west wind made it easy to trigger wind-drifted snow. Alex kicked these drifts which cracked and moved. We expect similar conditions and instability with wind-loaded slops throughout our forecast area. Photo: GNFAC

On Mt Ellis (2/27/21) the snowpack has 20-40cm of depth hoar and facets at the bottom. Stability tests took a lot of force to collapse this layer, but it propagated (broke across the whole column) every time once initiated. This is a poor snowpack structure that makes large avalanche possible to trigger if you hit the wrong spot on a slope. Photo: GNFAC

The Friends of the Avalanche Center, in partnership with the City of Bozeman, put in a Beacon Park at Beall Park. It is located on the north side of the Beall building between N. Bozeman Ave. and the ice rink. Stop by with your avalanche transceiver and do a few practice rescue drills. Your partner will thank you. Photo: S. Regan

From Obs: "This slide on the ridge extends north from Blackmore above Blackmore lake. The slide was on a north-facing slope around 9,100'. The crown looked multiple feet deep and either meandered, partially hidden from view, by another ridge or a substantial second avalanche a hundred feet away." 

We saw this crown on 2/20/21. It likely broke 2/19 or 2/18. Photo: GNFAC

We saw this crown on 2/20/21. It likely broke 2/19 or 2/18. Photo: GNFAC

"Here’s one more photo of some of the lower crown of that slide up Flanders. It was deep down lower!" Photo: S. Reinsel

From obs [2/20/21]: "We observed a large natural slide on Flanders Mountain that likely occurred on Thursday (2/18/21). The crown ranged from 2-5’, but it’s hard to gauge how wide it was, because it covered a lot of elevations. I think there is considerable overlap with the large slide that ran there earlier this season. We did not observe any other slides, collapsing, or cracking, but the wind did pick up in the early afternoon." Photo: S. Reinsel

From obs [2/20/21]: "We observed a large natural slide on Flanders Mountain that likely occurred on Thursday (2/18/21). The crown ranged from 2-5’, but it’s hard to gauge how wide it was, because it covered a lot of elevations. I think there is considerable overlap with the large slide that ran there earlier this season. We did not observe any other slides, collapsing, or cracking, but the wind did pick up in the early afternoon." Photo: S. Reinsel

From email: "I toured into Blackmore [2/19/21] and observed an old snow avalanche at 9600' on the east face of Mt Blackmore. I was there the day before and didn't see any evidence of avalanche activity; strong overnight winds with ample snow available for transport appeared to be enough to tip the scales." Photo: T. Guarino

From email: "I toured into Blackmore [2/19/21] and observed an old snow avalanche at 9600' on the east face of Mt Blackmore." Photo: T. Guarino

From email: "I toured into Blackmore [2/19/21] and observed an old snow avalanche at 9600' on the east face of Mt Blackmore. I was there the day before and didn't see any evidence of avalanche activity; strong overnight winds with ample snow available for transport appeared to be enough to tip the scales." Photo: T. Guarino

From email: "I toured into Blackmore [2/19/21] and observed an old snow avalanche at 9600' on the east face of Mt Blackmore. I was there the day before and didn't see any evidence of avalanche activity; strong overnight winds with ample snow available for transport appeared to be enough to tip the scales." Photo: T. Guarino

From e-mail:  "...a photo of what appeared to be a natural D2 underneath the Maid today [2/19/21]." Photo: H. Coppolillo

From obs: "The southwest corner of the cirque slid on the storm slab and broke 1200-1500’ wide, an east aspect had a crown that exceeded 6’ in places, and the south face of Divide Peak broke 2-6’ deep and ran full track. I observed no collapsing or cracking, but the signs of instability were still pretty clear." Photo: S Reinsel

From obs: "The southwest corner of the cirque slid on the storm slab and broke 1200-1500’ wide, an east aspect had a crown that exceeded 6’ in places, and the south side of Divide broke 2-6’ deep and ran full track. I observed no collapsing or cracking, but the signs of instability were still pretty clear." Photo: S Reinsel

From obs: "The southwest corner of the cirque slid on the storm slab and broke 1200-1500’ wide, an east aspect had a crown that exceeded 6’ in places, and the south side of Divide broke 2-6’ deep and ran full track. I observed no collapsing or cracking, but the signs of instability were still pretty clear." Photo: S Reinsel

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."

From Obs: "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

This natural avalanche broke under the new snow on a north facing hill at 8,500'.  Photo: GNFAC

This avalanche follows the treed ridgeline. It broke hundreds of feet wide, likely under the new snow.  SE aspect, 8,800'. Photo: GNFAC

This natural avalanche broke under the 3' of new snow that fell in the last week. NE aspect, 9,200'. Photo: GNFAC

On several steep slopes we saw widespread cracking that occurred as new snow loaded the weak snowpack. Photo: GNFAC

On 2/7/21 skiers in Beehive reported: "Numerous large collapses, ECTP in several pits on mid-pack facets, and triggered a test slope remotely from flat terrain. It broke in the old snow, but towards to top, maybe 10cm below the interface with the last week’s snow. Propagated over 50m, crown depth 60-100 cm. Would be solid size 2 if the slope wasn’t 20m tall." Photo: Sam H.

From obs 2/6/21: "Natural slide below Maid of the Mist (unless someone was up climbing Maid No More...). E/NE aspect, roughly 8000' elevation. Looked to have run last night or early this morning. Poor resolution iphone photo, but gets the job done. Photo taken from the base of the Dribbles." Photo: M. Zia

From obs: "Skied up into Divide Basin today... Observed 2 natural avalanches on the N face of the cirque, one quite large.... Shortly after digging the pit, on the same slope 30’ above it we triggered a slab that cracked but did not move..." Photo: J. Dalimata