From obs 12/18/21: "95cm Snow depth at around 9400’ 40cm of new snow on early December ice crust Ectx18 Will have to see with more loading on early December interface if it becomes reactive All alpine terrain was heavily stripped from the wind."
Northern Gallatin
East shoulder of divide pk
Date
Activity
Snowboarding
95cm Snow depth at around 9400’
40cm of new snow on early December ice crust
Ectx18
Will have to see with more loading on early December interface if it becomes reactive
All alpine terrain was heavily stripped from the wind
Region
Northern Gallatin
Location (from list)
Divide Peak
On 12/16/21 A skier in a group of three triggered and was caught in this avalanche next to The Apron at Bridger Bowl. The ski area is closed and backcountry conditions exist. Nobody was injured.
Lick Creek
Date
Activity
Skiing
Great Skiing out at Lick Creek today. I found 40cm of new snow (light wind effect on the easterly side) on the main south face that was sitting directly on the ground. The north aspect had a total depth on 90cm and closer to 30cm of new snow. The storm snow was right side up, starting at F and moving to F-. The only instability noted was a CT17Sc result where the new snow/old snow interface was. No propagation on ECT.
Region
Northern Gallatin
Location (from list)
Lick Creek
Observer Name
Nick Roe
Skiers up the East Fork of Hyalite Creek observed this small avalanche on a road cut. Photo: S. Reinsel
Forecast link: GNFAC Avalanche Forecast for Fri Dec 17, 2021
East fork Hyalite
Date
Activity
Skiing
I went on a xc ski up to Heather Lake today (my first ski of the season!), and thought I’d share what I saw. I expected to find signs of instability, given the new snow and our mediocre snowpack, but did not really see much to note. During the entire ski, I got one collapse on a small, shallow wind drift that was localized to within a foot of my ski. I observed a couple small sloughs off of higher terrain, but they failed to run very far or propagate into a slab. The only real activity I saw was on a west-facing road cut on the drive up (photo). This outing really didn’t give me enough information to ski off of—except to note that it is probably too early to ski—but the signs were encouraging.
Region
Northern Gallatin
Small, skier triggered wind slab
The Ramp
Bridger Range
Code
SS-ASu-R0
Elevation
8000
Aspect Range
E-NE
Latitude
45.82890
Longitude
-110.93100
Notes
My partner had a 6" deep, about 15' wide slab release roughly 40 feet beneath him about halfway up the ramp, lookers right, on a NE facing, untouched aspect. Seemed more in line with wolverine bowl aspect vs the ramp. We dug a pit just a little further up the ramp and got a little movement about 15cm's from the top of the pack but not solid enough to call it a clean break. 60-65cm total depth in our pit.
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
Trigger Modifier
u-An unintentional release
R size
0
Problem Type
Wind-Drifted Snow
Slab Thickness
6.0 inches
Vertical Fall
40ft
Slab Width
15.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year
From IG 12/12/21: @montanamountainmedicine
Collapses and Whumphs on NE Aspect 8000 feet in Hyalite
Hyalite - East Fork
Northern Gallatin
Code
AF-O
Elevation
8000
Aspect
NE
Latitude
45.45050
Longitude
-110.91900
Notes
From email obs: 12/12/21: "Shooting cracks and whoomphing in wind loaded areas. An approximately 15x30ft wind slab cracked along the bas of a rock band and settled at the base of P2 on high fidelity. Was triggered while traversing along the rock band to gain the second pitch, 1-2 inches of facets on the ground. Wind slab of 6-36in in the gullies."
(Second photo, believed to be from different group, sent on IG)
Number caught
0
Number buried
0
Trigger
Foot penetration
Bed Surface
O - Old snow
Problem Type
Wind-Drifted Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Red Flag
Advisory Year
From obs: 12/12/21: "Shooting cracks and whoomphing in wind loaded areas. An approximately 15x30ft wind slab cracked along the base of a rock band and settled at the base of P2 on high fidelity. Was triggered while traversing along the rock band to gain the second pitch, 1-2 inches of facets on the ground. Wind slab of 6-36in in the gullies." Photo: M. Hearley