We dug this snowpit in Denny Creek at the base of Lionhead Ridge near West Yellowstone on 12/22. An poor snowpack structure makes large avalanches possible to trigger. Photo: GNFAC
19-20
Skiers saw several old natural avalanches crowns in Republic Creek on 12/21. (all were E, or NE aspects). This one was seen last weekend (12/14). It broke near the ground and is now filled in by drifted snow. Photo: B. Fredlund
Avalanche Details: Natural in Republic Creek
Forecast link: GNFAC Avalanche Forecast for Mon Dec 23, 2019GNFAC Avalanche Forecast for Tue Dec 24, 2019
Cooke City, 2019-12-23
Forecast link: GNFAC Avalanche Forecast for Mon Dec 23, 2019GNFAC Avalanche Forecast for Tue Dec 24, 2019
Skiers saw several old natural avalanches crowns in Republic Creek on 12/21. (all were E, or NE aspects). Photo: B. Fredlund
Forecast link: GNFAC Avalanche Forecast for Wed Dec 25, 2019
Skiers saw these natural avalanche crowns in Republic Creek on 12/22. Photo: B. Fredlund
Human triggered hard wind slab near Fairy Lake
Fairy Lake
Bridger Range
Code
HS-AU-R4-D2-O
Latitude
45.90430
Longitude
-110.95800
Notes
Riders near Fairy Lake reported this slide on Saturday 12/21. Photo: @turbo_dieshall
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Unknown artificial trigger
R size
4
D size
2
Bed Surface
O - Old snow
Problem Type
Wind-Drifted Snow
Slab Thickness
42.0 inches
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year
Snowmobile remote triggered 5' deep wind slab
NORTHERN GALLATIN RANGE
Northern Gallatin
Code
HS-AMr-R2-D1.5-O
Latitude
45.47550
Longitude
-110.95000
Notes
From IG message: "5' thick wind slab just behind little bear remote triggered riding along the ridge." @skidooin_it
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Snowmobile
Trigger Modifier
r-A remote avalanche released by the indicated trigger
R size
2
D size
1.5
Bed Surface
O - Old snow
Problem Type
Wind-Drifted Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year
Large natural avalanche near Cooke City
Hayden Creek
Cooke City
Code
HS-N-R2-D2.5-O
Elevation
9800
Aspect
NE
Latitude
44.99180
Longitude
-109.91500
Notes
Skiers with a level 2 class near Cooke City reported: "...toured into East Hayden today with the Level 2 course. We noticed some recent natural activity on the S end of the Climax path (see photo).
We dug on a N aspect... around 9500'. HS 100 cm, CT22 SP down 60 cm on FC above the Thanksgiving crust. ECTP21 on the basal facet layer.
The students dug on E and W aspects... around 9800'. On both aspects HS was around 110-120 cm, and both the midpack FC/crust and basal facet layers were less reactive. Between six snowpits we didn't have a single ECTP, and only a handful of CT results on either layer.
All aspects were heavily wind affected."
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Natural trigger
R size
2
D size
2.5
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
24.0 inches
Vertical Fall
1100ft
Slab Width
600.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year
Large Collapse on hard wind slab in Hyalite
Flanders Creek
Northern Gallatin
Code
HS-AF-O
Elevation
7900
Aspect
NW
Latitude
45.43880
Longitude
-110.92600
Notes
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
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