20-21

From Obs: "Big whumf a cracking on south east slope 8000 feet elevation. sub 25 degrees angle. Super loud and scary when it fractured. Broke to the ground. Small crown up higher on same slope." Photo: A. Kaugman

Southern Gallatin, 2021-02-06

Large natural avalanche in Divide cirque

Divide Cirque
Northern Gallatin
Code
HS-N-R3-D2.5-O
Latitude
45.39340
Longitude
-110.96900
Notes

From skier in Divide Cirque on 2/6/2021: "In the basin, between pt 10,201 and 10,024 there was a very large avalanche that must have slid yesterday or last night. It looks like it propagated at least 1000’ wide and at the deepest the crown was easily 5 feet. Visibility was low so it was hard to tell, but it was definitely a big slide."

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Natural trigger
R size
3
D size
2.5
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
36.0 inches
Vertical Fall
600ft
Slab Width
1000.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Froma skier that tooured in divide cirque today. "In the basin, between pt 10,201 and 10,024 there was a very large avalanche that must have slid yesterday or last night. It looks like it propagated at least 1000’ wide and at the deepest the crown was easily 5 feet. Visibility was low so it was hard to tell, but it was definitely a big slide." Photo: N. Salsburg

Northern Gallatin, 2021-02-06

Ross Peak

Date
Activity
Skiing

Did several laps on eastern flanks of Ross Peak.

Observations for 6600’ to 8300’, E and NE aspects:

- Saw several natural dry loose avalanches (D1) on upper NE face of Ross
- No slab avalanches observed
- Observed at least two dozen whumphs (mostly small and localized) while skinning
- no cracking
- winds were steady moderate in the afternoon, lots of blowing and drifting snow observed; winds primarily from W but also NW and N
- average ski pen around 30 cm

Region
Bridger Range
Location (from list)
Ross Peak
Observer Name
Alexis Alloway

Maid of the Mist, Hyalite

Date
Activity
Ice Climbing

Natural slide below Maid of the Mist (unless someone was up climbing Maid No More...). E/NE aspect, roughly 8000' elevation.

Looked to have run last night or early this morning. Poor resolution iphone photo, but gets the job done. Photo taken from the base of the Dribbles.

Region
Northern Gallatin
Location (from list)
Hyalite - main fork
Observer Name
matt zia

Divide Peak Basin

Date
Activity
Skiing

Skied up into Divide Basin today and holy shit there is so much snow! 3’ of new on top of a crust that is present on S faces and not present elsewhere that we found. Observed 2 natural avalanches on the N face of the cirque, one quite large. There is a picture of those. Also observed another natural avalanche on the SE face of the cirque that I was unable to get a good photograph because of clouds. We dug 2 pits and got an ECTX on both (one at 9300’ - 270 cm of snow, one at 9500’- over 300 cm of snow) on S/SE facing slopes less than 20 degrees. The one at 9500’ we had a hard time sawing through the hard crust that is under 3’ of new snow so it probably isn’t very accurate. Shortly after digging the pit, on the same slope 30’ above it we triggered a slab that cracked but did not move. Turned around right there and left. A good example of how feedback from pits is not necessarily the end all be all. I think the new snow will become more reactive as it settles into a more cohesive slab. We kept it overly conservative and I just want to say I appreciate you all!!!

Region
Northern Gallatin
Location (from list)
Divide Cirque
Observer Name
Jeanine Dalimata

Lower Wolverine Bowl Small Natural Avalanche

Date
Activity
Skiing

Signs of a small natural avalanche on lower wolverine bowl

Region
Bridger Range
Location (from list)
Wolverine Bowl
Observer Name
Chris Pruden

Specimen Creek

Date
Activity
Skiing

GNFAC,
Toured up Specimen Creek today, it’s starting to fill in down low. We got 5-6 good whumphs while skinning around. It was snowing S-1 all day with light winds. We saw a group skiing a low angle ridge with a fresh crown off to the side of the ridge where it’s steeper, maybe 10-20’ from their tracks. It looked very much like they remote triggered it but I can’t be sure. The slide was R1D1.5, definitely broke into old snow. They light was to flat to get a good photo.
Psyched on powder skiing!
Spencer

Region
Southern Gallatin
Observer Name
Spencer Jonas

YNP specimen creek

Date
Activity
Skiing

Big whumf a cracking on south east slope 8000 feet elevation. sub 25 degrees angle. Super loud and scary when it fractured. Broke to the ground.

Small crown up higher on same slope

Region
Southern Gallatin
Observer Name
Ari Kaugman