23-24

Cooke City Observations

Date

Widespread cracking and collapsing were observed both north and south of Cooke City. 

North of Cooke City Level 1 snowpits: 

Got multiple ECTPs 12-17 taps, 65 down. Got one ECTV. HS ranging from 110-165. 

9820' SW, Aspect, ECTP16 60cm down on small grain faucets

South of Cooke City Level 1 snowpits: 

Dug a total of 7 pits throughout the day and 5 got propogation <5. Failing on the same SH/Facet layer 30-45 down

South of Cooke City numerous avalanches were observed on E, W, and Northern aspects. These all likely happened during or following a recent storm on 01/18. We stepped off the skin track and remotely triggered a small slope above the creek below. Took a closer look and it failed on surface hoar/facets 35 cm down. A skier-triggered avalanche was also seen on the west side of Woody Ridge. 

Region
Cooke City
Location (from list)
COOKE CITY
Observer Name
Beartooth Powder Guides

Cooke City, current snow obs

Date
Activity
Skiing

Ski toured to west Woody Ridge today, south of Cooke City. 

We set a new skin track and I would estimate that 80%+ of the snow we touched created a large collapse/ whompf.  Many of the collapses were large and loud (over 100' wide).  It seemed like remotely triggering an avalanche would have been easy/ likely had we been connected to steeper slopes.

We noted widespread avalanche activity in a nearby gully (NW aspects) adjacent ski tracks from yesterday.

In our snowpit at 9700', on a westerly aspect, we had an ECTPV.  On 2mm facets, 45cms down.

I've skied that area a lot over the last 15 years, commonly during big snowstorms and elevated avalanche hazard, but today seemed like one of the most hazardous, if not THe most hazardous days for avalanches I experienced there- given the widespread nature of the PWL and thickness and sensitivity of the slab.

The warm temperatures today likely had a significant influence on the instabilities.  (35 deg F in town for much of the afternoon.)  Lots of roof-a-lanches noted today as well.

Region
Cooke City
Location (from list)
Republic Creek
Observer Name
Beau Fredlund

Natural and Sled Triggered Slides in Cabin Creek

Cabin Creek
Southern Madison
Code
SS-AM
Latitude
44.90830
Longitude
-111.24000
Notes

Riders saw multiple natural avalanches on the ridge above Cabin Creek. They also experienced widespread cracking and triggered an avalanche on a small slope. 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Snowmobile
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Avalanches in Beehive and Middle Basin

Beehive Basin
Northern Madison
Code
HS-ASr-R1-D1.5-O
Aspect
E
Latitude
45.34070
Longitude
-111.39100
Notes

From obs: "My partner and I were traveling along the ridgeline separating Beehive and Middle Basin. 60 meters before the prayer flags on the ridge, we were stomping on the cornices. We heard a very loud whumphf and the cornice directly below me fell. This and our stomping triggered shooting cracks along the ridge and remotely triggered a cornice 30 meters ahead of us. This cornice fall triggered a hard slab avalanche that was about 15 meters wide and ran at least 100 hundred meters, but we could not see the terminus in the trees. The crown was 1F wind slab failing on facets 35 cm deep. It immediately stepped down to basal facets in spots with total crown depth of 75 cm. "


"We reached the east ridge of beehive basin at 11:30 and it was warming up quickly. We considered skiing east into middle just before the prayer flags, but when approaching the slope to dig a pit we got a significant collapse and decided to ski a more conservative pitch further north. When continuing north on the ridge we saw a recent cornice collapse which triggered an avalanche, size unknown but pictured here. The conservative east slope was in the shade and skied well.

on the way out we got another sizable collapse when skiing west down from prayer flags, on the shallow, sunny western slope, when I edged out of the gully at the first dog leg to regroup with the party."


"I saw a skier triggered slide on Tyler’s hill (lookers right of prayer flags gully), as I skinned in (ss-as-d1.5-r1-u). It looked  like it propagated across about 25 ft and just pulled out on the single roll over, I didn’t get real close, and figured a picture from that distance with trees in the way might not show much."


 

Number of slides
2
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Skier
Trigger Modifier
r-A remote avalanche released by the indicated trigger
R size
1
D size
1.5
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
35.0 centimeters
Slab Width
50.00ft
Slab Layer Grain Type
Wind Broken precipitation particles
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

From obs: "We considered skiing east into middle just before the prayer flags, but when approaching the slope to dig a pit we got a significant collapse and decided to ski a more conservative pitch further north. When continuing north on the ridge we saw a recent cornice collapse which triggered an avalanche" This avalanche was triggered by skiers breaking cornices on 01/20. Photo: M. Zenker

 

 

Northern Gallatin, 2024-01-20

From obs: "My partner and I were traveling along the ridgeline separating Beehive and Middle Basin. 60 meters before the prayer flags on the ridge, we were stomping on the cornices. We heard a very loud whumphf and the cornice directly below me fell. This and our stomping triggered shooting cracks along the ridge and remotely triggered a cornice 30 meters ahead of us. This cornice fall triggered a hard slab avalanche that was about 15 meters wide and ran at least 100 hundred meters, but we could not see the terminus in the trees. The crown was 1F wind slab failing on facets 35 cm deep.

Northern Madison, 2024-01-20