23-24

Skier triggered slab at Bridger

Bridger Bowl
Bridger Range
Code
SS-AS-R2-D1.5-I
Elevation
8300
Aspect
N
Latitude
45.81560
Longitude
-110.92300
Notes

From email 5/2/24: "Triggered in the virtues this evening. 40' wide, 4-12" deep, failed as a dense, wind-packed slab on the rain/sun/heat crust underneath the most recent snow.  I had marginal visibility but it looked like there were similar small-ish wind pockets that had failed in a few spots. Good skiing up high, fun first day up there."

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
R size
2
D size
1.5
Bed Surface
I - Interface between new and old snow
Problem Type
Wind-Drifted Snow
Slab Thickness
8.0 inches
Slab Width
40.00ft
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Skier triggered slab at Bridger

Date

From email 5/2/24: "Triggered in the virtues this evening. 40' wide, 4-12" deep, failed as a dense, wind-packed slab on the rain/sun/heat crust underneath the most recent snow.  I had marginal visibility but it looked like there were similar small-ish wind pockets that had failed in a few spots. Good skiing up high, fun first day up there."

Region
Bridger Range
Location (from list)
Bridger Bowl
Observer Name
Ben VandenBos

Avalanche on Beehive Basin Test Slope

Beehive Basin
Northern Madison
Code
SS-ASc-R1-D1-S
Aspect
W
Latitude
45.34070
Longitude
-111.39100
Notes

A skier triggered an avalanche on a test slope in Beehive Basin, breaking 12-16" deep and 75' across. The slide failed within the new snow. 

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
S - Avalanche released within new snow
Problem Type
New Snow
Slab Thickness
14.0 inches
Slab Width
75.00ft
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Avalanche on Beehive Basin Test Slope

Date
Activity
Skiing

A skier triggered an avalanche on a test slope in Beehive Basin, breaking 12-16" deep and 75' across. The slide failed within the new snow. 

Region
Northern Madison
Location (from list)
Beehive Basin

Large avalanche near Wolverine cirque

Wolverine Bowl
Bridger Range
Code
N
Latitude
45.83010
Longitude
-110.93400
Notes

On 5/4/24 “…. a friend toured around Wolverine today. On his way out he heard a slide breaking trees (just before noon). Unknown location but he said it sounded like it was around/ above Texas Meadows. The action continues!”

Number of slides
1
Number caught
0
Number buried
0
Trigger
Natural trigger
Problem Type
Wet Snow
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Natural wind slab North side of Wolverine

Wolverine Peak
Cooke City
Code
SS-N-R1-D1.5
Elevation
9500
Aspect
N
Latitude
45.05300
Longitude
-110.01000
Notes

From obs. 5/2/24: "Wind load on old crust, probably from Wednesday."

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
1
D size
1.5
Problem Type
Wind-Drifted Snow
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Large avalanche in northern Gallatin

Date

Saw a very large crown on a north face of a peak west of the hyalite area. Potentially peak 9662. The crown appears to wrap around multiple aspects for about 1/4 mile. Seen from the Bridgers around noon on May 4th. Probably went during this weeks storm, but it looks to me like it was much deeper than a storm slab.

Region
Northern Gallatin
Location (from list)
NORTHERN GALLATIN RANGE
Observer Name
Pat H.

Large avalanche near Wolverine cirque

Date
Activity
Skiing

On 5/4/24 “…. a friend toured around Wolverine today. On his way out he heard a slide breaking trees (just before noon). Unknown location but he said it sounded like it was around/ above Texas Meadows. The action continues!”

Region
Bridger Range
Location (from list)
Wolverine Bowl

Skier triggered large Wet loose on the fin

Republic Mountain
Cooke City
Code
L-ASu-R2-D2-I
Elevation
10000
Aspect
E
Latitude
45.00030
Longitude
-109.95400
Notes

From obs.: “Our party (3) triggered a significant wet loose slide on the fin today. I, the first skier dropped in next to existing tracks from earlier in the morning. I made a couple of small turns in unskied snow to test it and decided that not much was moving. As I continued down the wet surface snow started to slide and accumulate. My partner called me on the radio to tell me a lot of snow was moving behind me and I cut left. I traversed hard to lower angle terrain until I felt I could safely descend the rest of the slope.  My partners descended the bed surface until they could traverse out. 

We made several key mistakes today.  We knew it would be warm and that we should be up and down early.  We left later than planned, moved slower than expected and failed to adjust our plan.  We mistook lack of wet loose activity on similar aspects and elevations on features we could see as sign of stability.  We failed to make a plan B or establish a turnaround time.  We interpreted a party ahead of us that skied the slope as a go ahead.  Another party approaching behind us added pressure to go. They also skied the slope after us in similar style to my partners.

In our favor, we communicated well, radios were key, stayed calm and we managed ourselves through the situation. I feel humbled and lucky to have gotten away with a free lesson.  One that I didn't think I should have needed.”

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Loose-snow avalanche
Trigger
Skier
Trigger Modifier
u-An unintentional release
R size
2
D size
2
Bed Surface
I - Interface between new and old snow
Problem Type
Wet Snow
Slab Thickness
6.0 inches
Vertical Fall
900ft
Slab Width
250.00ft
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year