24-25

Sluffing in new snow

Date
Activity
Skiing

Took a quite tour up The Ramp to see how the new snow is bonding. Found 3-5" of new snow. Non-cohesive and seemed well bonded to the surfaces beneath. No signs of wind effect. No slab avalanches or signs of instability noted.

Saw a few sluffs in the new snow triggered by skiers in the very steep terrain just north of the Bridger Bowl ski area boundary (see photo). These sluffs were small, definitely not large enough to bury someone.

Region
Bridger Range
Location (from list)
The Ramp
Observer Name
Hoyer

PWL Avalanche in Muddy Creek

Buck Ridge
Northern Madison
Code
SS-R3-D2-O
Elevation
8700
Aspect
E
Latitude
45.17190
Longitude
-111.38000
Notes

In nearly 45 miles of riding, we noted two avalanches. Both breaking on persistent weak layers a few feet down in the snowpack. The first was a small north-facing pocket in the First Yellow Mule (R1-D1) that was snowmobile triggered. It looked to be around a week old. The second was a larger avalanche (R3-D2), east-facing, deep in Muddy Creek. This was drifted in and likely broke around 2.5 weeks ago during the last significant storm cycle. 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
R size
3
D size
2
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Vertical Fall
400ft
Slab Width
500.00ft
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Small PWL Avalanche in First Yellow Mule

Buck Ridge
Northern Madison
Code
SS-AMu-R1-D1-O
Elevation
9000
Aspect
N
Latitude
45.17190
Longitude
-111.38000
Notes

In nearly 45 miles of riding, we noted two avalanches. Both breaking on persistent weak layers a few feet down in the snowpack. The first was a small north-facing pocket in the First Yellow Mule (R1-D1) that was snowmobile triggered. It looked to be around a week old. The second was a larger avalanche (R3-D2), east-facing, deep in Muddy Creek. This was drifted in and likely broke around 2.5 weeks ago during the last significant storm cycle.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Snowmobile
Trigger Modifier
u-An unintentional release
R size
1
D size
1
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
18.0 inches
Vertical Fall
20ft
Slab Width
20.00ft
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Low Danger in the N Madisons

Date
Activity
Snowmobiling

We rode along Buck Ridge, dropping into First, Second and Third Yellow Mules. We looked into Bear Creek and McAtee Basin drainages before riding through Muddy Creek to the Yellowstone Club boundary. Throughout our ride, we noted tracks nearly everywhere, including many steep slopes. 

In nearly 45 miles of riding, we noted two avalanches. Both breaking on persistent weak layers a few feet down in the snowpack. The first was a small north-facing pocket in the First Yellow Mule (R1-D1) that was snowmobile triggered. It looked to be around a week old. The second was a larger avalanche (R3-D2), east-facing, deep in Muddy Creek. This was drifted in and likely broke around 2.5 weeks ago during the last significant storm cycle. We dug a snowpit near the lower flank of the path and noted that these weak layers had gained strength over time. We did get propagation on a stout melt-freeze crust near the surface (ECTP5) but did not get propagation lower down on faceted grains. 

Currently, these two PWL avalanches are the only PWL avalanches we have seen/have been reported to us in this area this season. This zone seems to be the northernmost extent of the PWL problem that we are dealing with further south in Lionhead, S. Madisons and S. Gallatins. 

Outside of these older two avalanches, we noted no other signs of instability and had a great day of riding. 

Region
Northern Madison
Location (from list)
Buck Ridge
Observer Name
H. Darby

Pit near Zimmer Creek

Date
Activity
Skiing

Dug a pit at 9650ft on a 20° NE facing slope near Zimmer Creek. HS 210-230. ECTN14 at about 40cm down.  

Region
Cooke City
Location (from list)
Zimmer Creek
Observer Name
N Mattes