18-19

Skier triggered avalanche in Beehive Basin

Beehive Basin
Northern Madison
Code
SS-ASu-R2-D2-I
Elevation
9000
Aspect
NE
Aspect Range
ENE
Latitude
45.34220
Longitude
-111.39700
Notes

From an email:

"Dug a pit at ~9000’ on a NE aspect, got a ECTP29 at 56cm down, breaking below the new snow and a 12cm knife-hard slab. Broke on small facets (<1mm) in between wind slabs. I marked the trigger point in red. Skinned up a low angle gully up to around 9500’. As I got near the steepest part of the gully (38°), a soft slab 12-18” thick propagated 100’ wide and slid 500’ back down to my pit. No one was caught. Contrary to my pit, this ENE aspect slid just the new snow on top of a previous wind slab. No facets on the bed surface, just new snow/old snow interface. Found safer skiing down low in the trees where there was less wind loading."

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab 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
New Snow
Slab Thickness
16.0 inches
Vertical Fall
500ft
Slab Width
100.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Cracking wind drifts on Mt Blackmore

Mt Blackmore
Northern Gallatin
Code
Latitude
45.44410
Longitude
-111.00300
Notes

From an email, " Over a foot of new snow up high with consistent NW winds.  Soft slabs where breaking anywhere from several inches midslope to a foot deep along ridgelines on a mid-storm density change in the newest snow.  We experienced cracking along ridgelines, but no collapsing while skinning in the trees or near the ridge."

Number of slides
1
Number caught
0
Number buried
0
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Avalanche occurred on 21 January. From email: "As we entered the large open meadows on the east face ... we remotely triggered a sizable avalanche from 2-300 yards away. The crown was approximately 100 yards wide, running several hundred yards downhill ... the crown appeared to be about 2 feet deep." Photo: G. Antonioli

Northern Gallatin, 2019-01-22

Natural avalanche on Football Field

Saddle Peak
Bridger Range
Code
SS-NC-R2-D2-S
Elevation
8700
Aspect
E
Latitude
45.79770
Longitude
-110.93400
Notes

Natural avalanche reported by ski patrol. Occurred around 1230. Likely cornice triggered. Strong winds blowing all day, drifting 20” of snow from the weekend. 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Cornice fall
R size
2
D size
2
Bed Surface
S - Avalanche released within new snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Natural avalanches Bridger pk. through Pinnacles

Bridger Peak
Bridger Range
Code
SS-N-R3-D2-I
Elevation
8900
Aspect
E
Latitude
45.77720
Longitude
-110.93600
Notes

Forecaster obs: This morning on drive to Bridger we saw crowns from recent avalanches almost continuously between Bridger Peak and the Pinnacles. Probably 6 paths had avalanches. 2-3’ deep across all starting zones. Estimate they ran late yesterday or this morning due to not very covered from yesterday’s snow, and crowns from Sunday on Saddle/Argentina were covered. Saddle was in a thick cloud of blowing snow. Strong wind continued all day. Moving across mid mountain later in the day. -AM

Multiple Avalanches
Number of slides
6
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
3
D size
2
Bed Surface
I - Interface between new and old snow
Problem Type
New Snow
Slab Thickness
30.0 inches
Vertical Fall
2000ft
Slab Width
200.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year