22-23

Buried Weak Layers in Cooke

Date
Activity
Snowmobiling

We rode up to Henderson Bench and then rode up the Goose Lake drainage. We dug two pits today, and we found buried weak layers that failed and propagated in both pits. On Henderson Bench (NE aspect) there was 7’ of snow (HS 213 cm), and we got an ECTP28 on a layer of buried surface hoar 2.5’ below the surface. We also dug on a west aspect above Goose Creek. There was 6’ of snow (HS 190 cm). The 14” of new snow had a SWE of 1.7”. Here, we got an ECTP 14 on a layer of near surface facets and surface hoar 1.5’ below the surface. After two days of finding buried weak layers that failed and propagated on different aspects, it’s apparent that triggering an avalanche on these buried weak layers is possible throughout the area.

Region
Cooke City
Location (from list)
COOKE CITY
Observer Name
Dave Zinn, Alex Haddad

Natural Avalanche Northern Madisons

Date

While driving to work from Ennis on Jack Creek Rd, I observed a natural avalanche occurring on an unnamed peak.  Approx location is 45 22' 57"N 111 28' 49"W at approx. 9000'

Region
Northern Madison
Location (from list)
NORTHERN MADISON RANGE
Observer Name
Jim Giglinto

Small skier triggered storm slab

COOKE CITY
Cooke City
Code
SS-ASc-R1-D1-I
Latitude
45.02020
Longitude
-109.93800
Notes

Some photos of recent natural avalanche activity near Cooke City attached.  We observed about 10 slab avalanches today that ran during this cycle.

.... And I was able to intentionally trigger a small storm slab today (20' wide, 1' deep) by kicking a small cornice.
 
Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
Trigger Modifier
c-A controlled or intentional release by the indicated trigger
R size
1
D size
1
Bed Surface
I - Interface between new and old snow
Problem Type
New Snow
Slab Thickness
12.0 inches
Vertical Fall
50ft
Slab Width
20.00ft
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Large Cracks near Ice climb in Hyalite

Flanders Creek
Northern Gallatin
Code
N
Elevation
8000
Latitude
45.44020
Longitude
-110.93100
Notes

From text: "went up to Champagne Sherbet to ice climb but then there was a big fracture on the approach! Got to a safe spot and dug to see - a strange drifted wind slab over the old belay area has created a scary snow cave trap! We bailed out of there..."

Number of slides
0
Number caught
0
Number buried
0
Trigger
Natural trigger
Problem Type
New Snow
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Red Flag
Advisory Year

From text: "went up to Champagne Sherbet to ice climb but then there was a big fracture on the approach! Got to a safe spot and dug to see - a strange drifted wind slab over the old belay area has created a scary snow cave trap! We bailed out of there..."

Northern Gallatin, 2023-01-30

Large Cracks near Ice climb in Hyalite

Date
Activity
Ice Climbing

From text: "went up to Champagne Sherbet to ice climb but then there was a big fracture on the approach! Got to a safe spot and dug to see - a strange drifted wind slab over the old belay area has created a scary snow cave trap! We bailed out of there..."

Region
Northern Gallatin
Location (from list)
Flanders Creek

Natural slide along Jack Creek Road

Lone Mountain
Northern Madison
Code
SS-N-R3-D1.5-O
Elevation
8000
Latitude
45.27770
Longitude
-111.45100
Notes

From IG "Natural slide on southwest facing slope along Jack Creek Road in Moonlight Basin"

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
3
D size
1.5
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year