20-21

Texas Meadows, Bridger Range

Date
Activity
Skiing

I have several observations from today that I will recount. My first is my ETCP17, which my partner and I did at approximately 1:30pm. We had been skiing several short low angle meadows, but there was significant overhead hazard over a meadow we wanted to ski so we dug a pit at approximately 7800" on a directly east-facing slope. To determine if we could handle this risk, we dug a pit. Our pit was approximately 85cm deep, and we were mostly concerned with the older 35cm of mainly DH and large-grained facets (picture attached) interacting with the latest 50cm of new storm cycle snow. We got a very reactive ETCP17 with a Q1 level shear (photo attached) on that interface that told us to stay far away from any overhead hazard, so we skied down a meadow without any overheard hazard. At the base of this east south-east facing meadow, at approximately 7500" I started skinning back up the meadow towards our old skin track. I heard a very loud whumpf (photo attached) but could not see any cracks or other signs of collapse near my skin track. We followed my skin track back up to the top of the same meadow I skied, but this time descended the slightly more eastern-aspect of the meadow. Almost immediately, I realized the whumpf I had heard previously remotely triggered a series of 7-8 large cracks that ranged from 30-100 feet wide. These cracks failed on the same interface we got to propagate in our ETC test. As I carefully descended the meadow, I saw many more cracks throughout the slope from the same remote trigger event. Additionally, I triggered two more significant whumpfs with shooting cracks 10-40 feet wide. We determined our remote trigger was at least 300 feet away from where the snow collapsed and cracked, on a slightly more convex eastern aspect than what we had skied the first time we skied the meadow (photo attached). We decided the was our day-ender, for sure, and promptly descended back to our car.

Region
Bridger Range
Location (from list)
Texas Meadow
Observer Name
Laura Ippolito

Natural avalanches on Middle Basin Peak

Middle Basin
Northern Madison
Code
N-R2-D2
Latitude
45.34470
Longitude
-111.38600
Notes

From obs on 1/8/21: "Observed numerous natural avalanches that had slid before this most recent snow storm. All on n or ne aspects going on the basal facets. Up to D2ish"

Number of slides
1
Number caught
0
Number buried
0
Trigger
Natural trigger
R size
2
D size
2
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

N-NE face of in middle basin peak (butt crack)

Date
Activity
Skiing

Observed numerous natural avalanches that had slid before this most recent snow storm. All on n or ne aspects going on the basal facets. Up to D2ish

Region
Northern Madison
Location (from list)
Middle Basin
Observer Name
Ryan R Griffiths

Cinnamon Creek remotley triggered slide

Date
Activity
Skiing

Shooting cracks and collapsing on the entire ascent to the Cinnamon Creek Lookout. Remotely triggered a R2-D2.5 on descent. 2-3 foot crown. Slide path was on an East facing slope at 9000ft. Failed on the same persistent weak layer being seen across most regions of the forecast zone.

Region
Southern Madison
Observer Name
JT Schmitt

Just north of hard scrabble

Date
Activity
Snowmobiling

The bowl north of hardscabble. Calm today but lots of wind loading prior on lee sides everywhere in this area.

Region
Bridger Range
Location (from list)
Fairy Lake

Silver Creek

Date
Activity
Skiing

ECTP 27 85cm on 2-3mm NSF’s on W ridge of Meridian Peak 9800’ 30* slope. See video
As well as ASu from someone outside our group
Lower in Silver Creek 9350’ S facing 18-24” deep 60-70’ wide. Ran 500’ skier was able to regain skis and off slab 100’ below initiation.

Region
Cooke City
Observer Name
Ben Hoiness

Yellow Mountain

Date
Activity
Skiing

Loud whoomphs and collapses while skinning uphill, from the car until we turned around about 400ft below the summit. Snowpack felt extremely responsive and we carefully avoided all avalanche terrain.

Region
Northern Madison
Location (from list)
NORTHERN MADISON RANGE
Observer Name
Ben Farrar