23-24

natural avalanche on Mt. Republic/ Cooke City

Date

From email: "Natural avalanche from yesterday evening or last night.  

North facing aspect, with an interesting 3 tiered crown beginning around 8900'."

Region
Cooke City
Location (from list)
Mt Republic
Observer Name
Beau Fredlund

Multiple avalanches on Mt. Abundance

Mt. Abundance
Cooke City
Code
SS-ASr-D2-O
Elevation
9900
Aspect Range
NE-NW
Latitude
45.07220
Longitude
-110.02200
Notes

Three avalanches were triggered 20-50' away from low-angel terrain above by skiers on Mt. Abundance. 

 

From obs: "We observed three similar avalanches on Mt Abundance today (2/11). All were at about 9,900' and on NE-NW aspects. We were able to safely look at the crown of the first one, which was ~150' wide, 55cm deep, and with an HS of 145. It failed on 1-2 cm buried surface hoar. The other avalanches were on shallow unsupported rocky terrain. All were remote triggered from low angle terrain above, 20-50' away. One of the avalanches sympathetically released a gully and ran 800'."

Number of slides
3
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
Trigger Modifier
r-A remote avalanche released by the indicated trigger
D size
2
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
55.0 centimeters
Vertical Fall
800ft
Slab Width
150.00ft
Weak Layer Grain type
Surface Hoar
Weak Layer grain size
2.00mm
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

From obs: "We observed three similar avalanches on Mt Abundance today (2/11). All were at about 9,900' and on NE-NW aspects. We were able to safely look at the crown of the first one, which was ~150' wide, 55cm deep, and with an HS of 145. It failed on 1-2 cm buried surface hoar. The other avalanches were on shallow unsupported rocky terrain. All were remote triggered from low angle terrain above, 20-50' away. One of the avalanches sympathetically released a gully and ran 800'." Photo: A.

Cooke City, 2024-02-11

From obs: "We observed three similar avalanches on Mt Abundance today (2/11). All were at about 9,900' and on NE-NW aspects. We were able to safely look at the crown of the first one, which was ~150' wide, 55cm deep, and with an HS of 145. It failed on 1-2 cm buried surface hoar. The other avalanches were on shallow unsupported rocky terrain. All were remote triggered from low angle terrain above, 20-50' away. One of the avalanches sympathetically released a gully and ran 800'." Photo: A.

Cooke City, 2024-02-11

From obs: "We observed three similar avalanches on Mt Abundance today (2/11). All were at about 9,900' and on NE-NW aspects. We were able to safely look at the crown of the first one, which was ~150' wide, 55cm deep, and with an HS of 145. It failed on 1-2 cm buried surface hoar. The other avalanches were on shallow unsupported rocky terrain. All were remote triggered from low angle terrain above, 20-50' away. One of the avalanches sympathetically released a gully and ran 800'." Photo: A.

Cooke City, 2024-02-11

From obs: "We observed three similar avalanches on Mt Abundance today (2/11). All were at about 9,900' and on NE-NW aspects. We were able to safely look at the crown of the first one, which was ~150' wide, 55cm deep, and with an HS of 145. It failed on 1-2 cm buried surface hoar. The other avalanches were on shallow unsupported rocky terrain. All were remote triggered from low angle terrain above, 20-50' away. One of the avalanches sympathetically released a gully and ran 800'." Photo: A.

Cooke City, 2024-02-11

Natural Avalanche on Miller Ridge, Cooke City

Miller Ridge
Cooke City
Code
SS-N-R2-D2-O
Elevation
10000
Aspect
E
Latitude
45.04570
Longitude
-109.96600
Notes

Riders on 02/11/2024 observed two avalanches on the east side of Miller Ridge. These likely happened a few days prior near the end of a recent storm. 

From obs: "Natural avalanches observed on east facing aspect of Miller Ridge on 2/11. Larger avalanche propagated widely on the north end of the ridge around 10,000 ft. Smaller avalanche further south on the ridge as well. "

Number of slides
2
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
2
D size
2
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Remotely Triggered Avalanche, Middle Basin

Middle Basin
Northern Madison
Code
SS-ASr-R2-D2-O
Latitude
45.33740
Longitude
-111.38100
Notes

Skiers in Middle Basin remotely triggered two avalanches while crossing below them. One was triggered by the party breaking trail, the second by a 2nd party from the skin track

Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
Trigger Modifier
r-A remote avalanche released by the indicated trigger
R size
2
D size
2
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year