Forecast link: GNFAC Avalanche Forecast for Tue Dec 17, 2019
Forecast link: GNFAC Avalanche Forecast for Tue Dec 17, 2019
Northern Gallatin
Forecast link: GNFAC Avalanche Forecast for Tue Dec 17, 2019
Small slide in Hyalite
Divide Peak
Northern Gallatin
Code
SS-N-R1-D1-U
Latitude
45.40290
Longitude
-110.97600
Notes
While on a tour in Hyalite yesterday, we were able to find stable snow on a south aspect at 9500 feet. Although we found no propagation in our ECT, we observed a defined crust layer about 2.5 feet down which was well bonded to snow above. On some steeper pitches near rocks bands, we observed top layer slough that moved naturally. We also observed a small crown from a day or two ago that broke between two buried rocks and only ran about 50 feet down slope.
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
1
D size
1
Bed Surface
U - Unknown
Slab Thickness
12.0 inches
Vertical Fall
50ft
Images
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year
From e-mail:" While on a tour in Hyalite yesterday [12/15],... On some steeper pitches near rocks bands, we observed top layer slough that moved naturally. We also observed a small crown from a day or two ago that broke between two buried rocks and only ran about 50 feet down slope." Photo: Tommy S
Avalanche Details: Small slide in Hyalite
Northern Gallatin, 2019-12-16
Bridger patrol triggered large slides on heavily wind loaded slopes
Bridger Bowl
Bridger Range
Code
HS-ACc-R2-D3-O
Elevation
8500
Aspect
E
Latitude
45.81560
Longitude
-110.92300
Notes
Ski patrol triggered two large hard slab avalanches, one in Slushman's Ravine and the other in Mundy's Bowl, by knocking large cornices down on the slope. One was 4' deep, AC-HS-R2-D3-O, ran 1150' vertical. The other was 2.5' deep, AC-HS-R2-D2-O, ran 650' vertical. This was their first control in this area for the season, so the snowpack is similar to backcountry.
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Cornice fall triggered by human or explosive action
Trigger Modifier
c-A controlled or intentional release by the indicated trigger
R size
2
D size
3
Bed Surface
O - Old snow
Problem Type
Wind-Drifted Snow
Slab Thickness
36.0 inches
Vertical Fall
1000ft
Images
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year
The Bridger Bowl Ski Patrol triggered this slide on a heavily wind-loaded east facing slope at the ridgeline. They wrote, "With a shovel push the vertical cornice/pillow broke 15''-36'' deep on a steep and rounded bulge just south of Lee's Leap running on the crust. The debris terminated well below Pat's Chute." Its code is HS-AC-R2-D2-O-TR. Photo: BBSP