19-20

We skied Wheeler via South Cottonwood and found that the two gullies on the East and South East aspects had recently run in their entirety. We could only see the crown on the South East gully but it appeared to have broke on the steepest part of the slope near the top approximate 3-4ft deep and was the width of the gully. Both avalanches ran the full length and width of their gullies, breaking several trees along the way. The East debris pile was about 25ft deep and the South East was 15ft deep.

Northern Gallatin, 2020-02-16

2 slides in a week on Knowles Peak, Paradise Valley

Knowles Peak
Out of Advisory Area
Code
HS-N-R4-D3-O
Aspect
N
Latitude
45.30480
Longitude
-110.54300
Notes

1. "Large (presumably natural) avalanche seen on the north face of Knowles. 3ft deep crown, 300ft wide and probably a 100k ft run. Multiple broken trees in the debrisfield. Collapsing on 4" of sugary facets at the ground. Cracking, whoomphing, collapsing, etc found on all aspects on the ascent."

2. Photo is from February 12, Knowles Peak from Moo Creek.

Number of slides
2
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Natural trigger
R size
4
D size
3
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
36.0 inches
Vertical Fall
1000ft
Slab Width
300.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Snowbiker triggered slide in Taylor's Fork

Taylor Fork
Southern Madison
Code
SS-AMu-R2-D2-G
Latitude
45.06070
Longitude
-111.27200
Notes

Slide in Taylor’s fork crown of about 5-6’ and abou100' wide. Human triggered.

Number of slides
1
Number caught
1
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Snowmobile
Trigger Modifier
u-An unintentional release
R size
2
D size
2
Bed Surface
G - Ground
Problem Type
Persistent Weak Layer
Slab Thickness
60.0 inches
Vertical Fall
500ft
Slab Width
100.00ft
Weak Layer Grain type
Depth Hoar
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Natural avalanche east of the top of Lick Creek

Lick Creek
Northern Gallatin
Code
SS-N-R2-D1.5
Aspect
W
Latitude
45.52430
Longitude
-110.95600
Notes

From an observation, "This activity appears to have occurred naturally. No signs of a skin track or skiing. No accurate indication of when it happened, tho appeared fairly recent with no new wind loading." 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
2
D size
1.5
Problem Type
New Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Natural avalanche on Alex Lowe Peak

Alex Lowe Peak
Northern Gallatin
Code
HS-N-R4-D3-O
Elevation
9600
Aspect
N
Latitude
45.42720
Longitude
-111.01400
Notes

From an email:

"Near the ridge line of Mt. Blackmore we noticed the East facing slope close to the ridge line was clearly wind loaded and felt collapsing and cracking under our skis. None of those cracks shot out however. We dug a pit on an E- SE facing slope near the ridge line and found no signs of stability, however we ran into a group on our way up who said they dug a pit in a similar area and got an ECTP-22. Looking N-NW from the ridge line we saw some an avalanche crown on the adjacent face (Alex Lowe Peak)."

This is the second time this avalanche path released. See a photo from 1/25/20 HERE.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Natural trigger
R size
4
D size
3
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
48.0 inches
Vertical Fall
1000ft
Slab Width
1200.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year