24-25

Many natural wind slab avalanches and cornice falls

COOKE CITY
Cooke City
Code
SS-N-R1-D1.5
Aspect Range
E, N, NE, SE
Latitude
44.96950
Longitude
-109.96300
Notes

We saw at least 3 rider triggered wind slabs, 4-5 natural wind slab avalanches, and a couple large cornice falls.

Number of slides
5
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
1
D size
1.5
Problem Type
Wind Slab
Slab Thickness
10.0 inches
Slab Width
30.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Remote triggered persistent slab east of Mt. Abundance

Mount Abundance
Cooke City
Code
HS-AFr-R3-D2-O
Elevation
8800
Aspect
NE
Latitude
45.08080
Longitude
-110.00400
Notes

We went to look at an avalanche that was triggered two days ago, remotely from flat terrain above a steep slope, on the northeast end of Mt. Abundance. While looking for the avalanche from the flat bench above we triggered a similar sized slide directly adjacent to the previous slide. They broke on weak layers of facets and surface hoar that formed at the end of January. 2-3 feet deep and 150-200' wide. 1F to P- hard slab above the weak layer with 25cm of 4F to F snow at the surface. AFr-HS-R3-D2-O.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Foot penetration
Trigger Modifier
r-A remote avalanche released by the indicated trigger
R size
3
D size
2
Bed Surface
O - Old snow
Problem Type
Persistent Slab
Slab Thickness
65.0 centimeters
Vertical Fall
400ft
Slab Width
200.00ft
Weak Layer Grain type
Surface Hoar
Weak Layer grain size
5.00mm
Slab Layer Grain Type
Decomposing and Fragmented precipitation particles
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

On Feb 24 we saw at least 3 rider triggered wind slabs, 4-5 natural wind slab avalanches, and a couple large cornice falls. Strong wid had affected almost every piece of terrain, scouring some slopes, loading others, just stiffening the slab in many areas, and forming fresh drifts on every convex roll and along the edges of trails. Riding was still soft and fairly consistent in many areas. Photo GNFAC

Cooke City, 2025-02-24

On Feb 24 we saw at least 3 rider triggered wind slabs, 4-5 natural wind slab avalanches, and a couple large cornice falls. Strong wid had affected almost every piece of terrain, scouring some slopes, loading others, just stiffening the slab in many areas, and forming fresh drifts on every convex roll and along the edges of trails. Riding was still soft and fairly consistent in many areas. Photo GNFAC

Cooke City, 2025-02-24

On Feb 24 we saw at least 3 rider triggered wind slabs, 4-5 natural wind slab avalanches, and a couple large cornice falls. Strong wid had affected almost every piece of terrain, scouring some slopes, loading others, just stiffening the slab in many areas, and forming fresh drifts on every convex roll and along the edges of trails. Riding was still soft and fairly consistent in many areas. Photo GNFAC

Cooke City, 2025-02-24

On Feb 24 we saw at least 3 rider triggered wind slabs, 4-5 natural wind slab avalanches, and a couple large cornice falls. Strong wid had affected almost every piece of terrain, scouring some slopes, loading others, just stiffening the slab in many areas, and forming fresh drifts on every convex roll and along the edges of trails. Riding was still soft and fairly consistent in many areas. Photo GNFAC

Cooke City, 2025-02-24

On Feb 24 we saw at least 3 rider triggered wind slabs, 4-5 natural wind slab avalanches, and a couple large cornice falls. Strong wid had affected almost every piece of terrain, scouring some slopes, loading others, just stiffening the slab in many areas, and forming fresh drifts on every convex roll and along the edges of trails. Riding was still soft and fairly consistent in many areas. Photo GNFAC

Cooke City, 2025-02-24

On Feb 24 we saw at least 3 rider triggered wind slabs, 4-5 natural wind slab avalanches, and a couple large cornice falls. Strong wid had affected almost every piece of terrain, scouring some slopes, loading others, just stiffening the slab in many areas, and forming fresh drifts on every convex roll and along the edges of trails. Riding was still soft and fairly consistent in many areas. Photo GNFAC

 

Cooke City, 2025-02-24

While looking for a recent avalanche from the flat bench above we triggered a similar sized slide directly adjacent to the previous slide. They broke on weak layers of facets and surface hoar that formed at the end of January. 2-3 feet deep and 150-200' wide. Photo: GNFAC

Cooke City, 2025-02-24

While looking for a recent avalanche from the flat bench above we triggered a similar sized slide directly adjacent to the previous slide. They broke on weak layers of facets and surface hoar that formed at the end of January. 2-3 feet deep and 150-200' wide. Observing the snowpack that caused the avalanche. Photo: GNFAC

Cooke City, 2025-02-24