Regional Conditions for Southern Gallatin

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

From obs (2/28/21): "I’ve attached a photo of a small, D1.5, slide I saw on a thin S facing slope at 9000’. It was definitely more than a few days old. HS in the areas you would want to ski is 130-180cm, with a distinct drop felt with a probe at the bottom of the pack. Other areas are very scoured up there." S. Jonas

Riders triggered this slide on 2/28/21 near Red Canyon/Cabin Creek, north of West Yellowstone. Nobody caught or injured, but close call.

Riders triggered this slide on 2/28/21 near Red Canyon/Cabin Creek, north of West Yellowstone. Nobody caught or injured, but close call.

Riders triggered this slide on 2/28/21 near Red Canyon/Cabin Creek, north of West Yellowstone. Nobody caught or injured, but close call.

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

From obs: "Observed 2 natural avalanches, both on the basal persistent layer I would guess. one maybe a week old, partially filled in (SS-N-D1R2-O), and one that ran in the last 24 hrs (SS-N-D1.5R2-O) on a SE aspect, 35 deg at 8200 ft. I thought it was interesting given the lack of new snow and seeming lack of strong winds in this area." Photo: S. Hennessey 

From obs: “Triggered a large slide with a snowmobile. Went all the way to the ground. Crown seemed to range anywhere from maybe 3 ft to 10 ft. Large slabs of snow broke free and slid for about 100 yards.”

On 2/13/21 riders reported they triggered this avalanche, and remotely triggered two other slides. Nobody was injured. One partially buried.

On 2/13/21 riders reported they triggered this avalanche, and remotely triggered two other slides. Nobody was injured. One partially buried.

Sledders triggered this slide on 2/6/21 in West Targhee Creek near Lionhead. No one was caught.

From Obs: "Big whumf a cracking on south east slope 8000 feet elevation. sub 25 degrees angle. Super loud and scary when it fractured. Broke to the ground. Small crown up higher on same slope." Photo: A. Kaugman

From Obs: "Skied up near Big Horn Peak today, around 100cm HS, a bit unsupportable and thin down low. Got lots of whumphs, probably 20+. Saw an avalanche on the west face of Meldrum, looked to be a few days old, but probably R2D2." Photo: S Jonas

A snowmobiler triggered this avalanche on Monday (2/1/2021) at Lionhead. No one was caught. Photo: Anonymous

A snowmobiler triggered this avalanche on Monday (2/1/2021) at Lionhead. No one was caught. Photo: Anonymous

This small avalanche was below the corner of Lionhead peak. It was one of the smaller slides during the avalanche cycle that occurred 1/29 and 1/30. Photo: GNFAC

The avalanche broke in the new snow, but stepped down into deeper layers (sugary facets) mid-path. This can occur when there are multiple weak layers in the snowpack. Photo: GNFAC

Every path along the shoulder of Targhee Peak (Lionhead area) avalanched naturally during the storm 1/29 and 1/30. Photo: GNFAC

This steep north facing slope avalanched about 3 weeks ago on depth hoar when a snowmobiler triggered it. It got reloaded with new snow and wind drifts and avalanched a second time! Photo: GNFAC

This natural avalanche occured on a NE facing slope at 8600". It was 2' deep, 500' wide and 250' vertical. The avalanche broke on a thin layer of facets during the storm. SS-N-R3-D2-O. Photo: GNFAC

On the north end of Lionhead Ridge is Airplane Bowl. The crown line extends across the entire bowl on the right with a separate avalanche on the left. Photo: GNFAC

Take a close look at the picture and you'll see crowns from the far left to the far right of the photograph. Photo: GNFAC

Many avalanches broke under the new snow and also deeper on facets. These natural slides occurred on 1/29 and 1/30. Photo: GNFAC

Skiers remotely triggered this slide, from low angle terrain, below and far to the side on 1/30/21. It is on Ernie Miller ridge near Bacon Rind on E aspect around 9,000' elev. Click below for more info.

Skiers remotely triggered this slide, from low angle terrain, below and far to the side on 1/30/21. It is on Ernie Miller ridge near Bacon Rind on E aspect around 9,000' elev. Click below for more info.

Skiers reported widespread collapsing and cracking of the snowpack, breaking on weak sugary snow near the ground, and said, "snow was falling off trees hundreds of feet away with some collapses." Photo: E. Knoff

This avalanche was triggered on 1/30/21 by skiers from low angle terrain adjacent to the slope, and a long ways away. Photo: G. Stevens

From obs: "While skiing a loaded east aspect in the Southern Gallatin, my partner got a large collapse as he started to break trail back to our skin track, cracks shot 20ish feet uphill." Photo: A. Palombo

From obs: "The NE facing slopes of Dudley Creek are struggling to hold the new snow. I easily triggered the 6-8" of new and windblown snow but it is also stepping down to the facets buried deeper." Photo: S. Budac

Stepping out of my skis I sunk to the ground. The snowpack is weak and unsupportable. Large grains of sugary facets (depth hoar) make up the bottom third of the snowpack. Photo: GNFAC

Snowfall and strong wind triggered this avalanche on 1/13/2021. Photo: B. Fredlund

Cracking, collapsing, wumphs in the Southern Gallatin. ECTP 22. West facing, 8200’ non windloaded, 80cm of snow. Broke 50cm deep on depth hoar. Barely a cohesive slab on top but still enough to cause unstable conditions.

We looked at the avalanche in Hyalite that was triggered on Saturday 1/9/21. The slope angle was 33-35 degrees. It broke 2-3’ deep on weak facets below a hard slab, 1000’ wide and the debris was 5-9’ deep. East aspect, 9,800’ elevation. Photo: GNFAC

Skiers triggered this avalanche on Flanders Mountain on 1/9/21. It was triggered out of the photo to the right on a seperate slope around the corner. It propagated over 1000' wide, and 2-4' deep. Photo: GNFAC