Regional Conditions for Northern Gallatin

From obs: 5/9/21: "Yesterday we went to check out the new snow in Beehive Basin... Looking down into the face of Peruvian, we observed a natural dry loose slide that released from the ridge... We observed an increase in wind speed throughout the morning, and a shift in wind direction from west to southwest in the early morning moving to west to north west by the late morning. The combination of variable and high winds with the amount of new snow available for transport created a noticeable increase in the hazard of wind slabs on all aspects we observed during the morning..." Photo: E. Schreier

From obs: 5/9/21: "Yesterday... While traversing... along the north ridge of 10602 [in Beehive], we triggered a small wind slab  that carried down into Peruvian, which then released another small wind slab on a northeast aspect of the face (photo). The crown height of this wind slab was measured at 60cm at it's deepest point, and approximately 30ft wide by 10ft long. Looking down into the face of Peruvian, we observed a natural dry loose slide that released from the ridge. We observed an increase in wind speed throughout the morning, and a shift in wind direction from west to southwest in the early morning moving to west to north west by the late morning. The combination of variable and high winds with the amount of new snow available for transport created a noticeable increase in the hazard of wind slabs on all aspects we observed during the morning..." Photo: E. Schreier

Small wet loose slide that a skier triggered, running over an older crown from prior days. East aspect, 10,000'. From 5/7/21. Photo: D. Britt

Photo of a large natural wet avalanche in Taylor Fork, NNW aspect around 9,000' elevation near Koch Peak, on 5/3/21. Photo: D. Britt

From email 5/2/21: "Small but plentiful wet snow avalanches in Cooke City today. Didn’t see any that were broke on a deeper scale." Photo: K. Goodyear

From obs: "I traversed the Bridger range yesterday (4/28/21). The alpine start was good and solid but I saw lots of recent avalanches that looked super wet, some that had broken a couple feet deep. Conditions were pretty stable until about 1300 when that most recent snow layer started to really want to slide on the crust. Once I was in the meadows between Baldy and the M, at about 1400, I started hearing/feeling really wet "whumps". Photo: J. Harrison

From obs: "I traversed the Bridger range yesterday (4/28/21). The alpine start was good and solid but I saw lots of recent avalanches that looked super wet, some that had broken a couple feet deep. Conditions were pretty stable until about 1300 when that most recent snow layer started to really want to slide on the crust. Once I was in the meadows between Baldy and the M, at about 1400, I started hearing/feeling really wet "whumps". Photo: J. Harrison

From obs 4/28/21: "Observed numerous natural wet loose slides probably occurring over the past 48 hours on NW-W-S aspects mid-elevation. Point releases from rock bands and couloirs shedding. Photo for example, which shows W facing bowl with slides visible from US-89 in Paradise Valley. These are between 8500’ and 9500’ on an unnamed peak just northeast of Dexter Point." Photo: T. Benson

From obs (4/18/21): "...class split and dug three pits, one on NE, one on N, and one on NW at 7623'. HS averaged around 70 - 100 cms... The NE and NW facing pits showed rounding depth hoar and no sudden CT results. None of the ECTs fractured or propagated. The N facing slope still had preserved advanced depth hoar 3 mm in size (see image)..." Photo: J. Quinn

From obs 4/9/21: "...we saw widespread natural wind slabs on N-NE eastern slopes in the Northern Absarokas (photo). Winds increased throughout the morning, and evidence of wind transport became more apparent at higher elevations. We found that on aspects unaffected by wind loading, the new snow layer was not cohesive and only saw minor sluffing." Photo: E. Schreier

Skiers had a collapse which made this crack on a south facing slope with a shallower, wet snowpack around 9,000' near Cooke City. Photo: J. Redfield

This wet slab was reported on 4/4/21 around 8,200' elevation in the Main Boulder drainage south of Big Timber, outside of our advisory area. It happened that day or very recently during extended above freezing temperatures. Photo: G. Smith

This was a natural wind-slab avalanche releasing below the upper cliffs on Saddle Peak on March 28th. Photo: Anonymous

Natural avalanches on wind loaded slope occurred on 3/28/21 in Hyalite. Photo: B. Greene

Extreme winds on 3/28/21 transported snow that fell over the past week into fresh wind slabs. Photo: BSSP

Natural avalanche observed at the head of Flanders creek on 3/27/21. Photo: D. Britt

From obs: "Observed a small skier triggered slide on the middle ridge of MT Blackmore today, skier was cutting across when it released." Photo: C Crowe

Skiers triggered this 4-6" deep wind slab in Hyalite on 3/27/21. Click link below for more info.

From obs: "Deep slab avalanche in Blackmore Basin that appeared to break on the depth hoar near the bottom of the snowpack. It was on a wind loaded NE facing slope at approx. 9,500 and looked to break on a slope in the 35-40 degree range. The crown was about 8'-10' deep and 200' wide. It broke to the ground and ripped out several small trees." Photo: JR Mooney

From obs: "Skied Mount Blackmore today (3/27/21)... around 1 pm a skier remote triggered a deep slab from ~50 feet away (around the corner lookers right in the attached picture). Broke at the ground, 10-15feet deep, and took out a small tree." Photo: M. Lavery

From obs: "Skied Mount Blackmore today (3/27/21). Saw a natural avalanche on Alex Lowe peak just south of the Hellmouth...". Photo: M. Lavery

From obs: "Skied Mount Blackmore today. Saw... 4 skier triggered slides on the E face between the Blackmore and Alex Lowe Basins. Most appeared to be wind slabs... " Photo: M. Lavery

Ian and Dave stop to do a quick stability test as they hunt for a layer of weak snow 1-2 feet under the surface. Photo: GNFAC

21 March 2021: A pair of skiers triggered this slide on the east face of Mount Blackmore. No one was caught. Photo: Anonymous

On Monday, March 22, skiers toured west of Blackmore Lake and observed a natural slide of the new snow below a cornice. Photo: E. Schreier

Skiers booting up the N Coulior of the Mummy (from Flanders), triggered this small 6" soft slab avalanche without consequence. Photo: H. Coppolillo

A pair of skiers were ascending the east-face of Alex Lowe Peak when they triggered an avalanche that broke 150' above them. One skier was caught and carried 250 vertical feet. No one was injured or buried.

A pair of skiers were ascending the east-face of Alex Lowe Peak when they triggered an avalanche that broke 150' above them. One skier was caught and carried 250 vertical feet. No one was injured or buried. Photo: Anonymous

From obs: "On our way up the summer trail route to Hyalite Peak our party of three remotely triggered a small avalanche from the skin track at around 9,600ft on a east facing aspect. The storm slab went about 4 inches deep and 150-200ft across a small roll over feature. We were about 150ft away when we triggered the slide." Photo: C. Kussmaul

Crown of deep slab avalanche on Arden Peak at the back of Maid of the Mist basin in Hyalite. Probably broke between Feb 22 and Feb 28, 2021 Photo: GNFAC

Deep slab avalanche on Arden Peak at the back of Maid of the Mist basin in Hyalite. Probably broke between Feb 22 and Feb 28, 2021 Photo: GNFAC

Deep slab avalanche on Arden Peak at the back of Maid of the Mist basin in Hyalite. Probably broke between Feb 22 and Feb 28, 2021 Photo: GNFAC

Deep slab avalanche on Arden Peak at the back of Maid of the Mist basin in Hyalite. Probably broke between Feb 22 and Feb 28, 2021 Photo: GNFAC

From obs 3/6/21: "Two large natural avalanches in Maid of the Mist Basin. One of them ran on the east face of Arden Peak (Peak 10,201) which propagated across the entire face. Could have been triggered by a cornice fall then stepped down to deeper layers. The second was on the NE face of the peak Fat Maid and Skinny Maid come from. Also propagated across the entire slope. Crown height between 6'-8' in most places." Timing of these slides is unknown. Probably in the last week, but maybe older. Photo: S. Enloe

From obs 3/6/21: "Two large natural avalanches in Maid of the Mist Basin. One of them ran on the east face of Arden Peak (Peak 10,201) which propagated across the entire face. Could have been triggered by a cornice fall then stepped down to deeper layers. The second was on the NE face of the peak Fat Maid and Skinny Maid come from. Also propagated across the entire slope. Crown height between 6'-8' in most places." Timing of these slides is unknown. Probably in the last week, but maybe older. Photo: S. Enloe

We saw these recent wet loose avalanches on 3/6/21. SW aspect, 9,100'. They likely ran during above freezing temperatures between 3/3 and 3/5. Photo: GNFAC

From obs: "Small D1 avalanche on south-eastern aspect around 7800ft. Looks like solar released on older layer a day or two ago."

Photo: M. Mailly

From obs: "While touring above the canyon this morning, I noticed a very recent wet slide (would guess this incident occurred yesterday afternoon, March 4th). This was a skier triggered slide on a E aspect at an elevation of 7200. This slide was roughly 50 feet wide and ran about 50 feet, I estimated this crown to be 2-3 feet deep, slid all the way to the ground. This occurred below a steep roller."

Photo: T. Saulnier

"On the drive back we saw a large crown on the NW face of Big Horn peak..." (likely broke Sat or Sun, 2/27-28). Photo:  S. Jonas