24-25

small loose snow slides N. Bridgers

The Throne
Bridger Range
Code
L-N-R1-D1-S
Elevation
8500
Aspect
S
Latitude
45.88220
Longitude
-110.95200
Notes

The new snow was low density and sluffed easily on steep shady northerlies. On steep slopes facing the sun (south and east, and probably west) the new snow sat on a crust and became moist as the sun warmed it up and started to slide under skis. We saw a couple very small natural loose snow slides below rock outcrops on south facing slopes. Air temperatures were well below freezing, especially with wind chill, but the sun quickly warmed the recent new snow.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Loose-snow avalanche
Trigger
Natural trigger
R size
1
D size
1
Bed Surface
S - Avalanche released within new snow
Problem Type
Loose Dry
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Fresh reactive wind slabs N. Bridgers

The Throne
Bridger Range
Code
SS-ASc-R1-D1-S
Elevation
8300
Aspect
SE
Latitude
45.88220
Longitude
-110.95200
Notes

There was 6" of low density snow from yesterday. Winds were stronger than expected, from the north at the top of the Throne, and increased through the morning.

We found fresh drifts that were reactive, cracking easily and 5-10' wide out from our skis, on south and east facing slopes around 8000-8300'.

Number of slides
2
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
Trigger Modifier
c-A controlled or intentional release by the indicated trigger
R size
1
D size
1
Bed Surface
S - Avalanche released within new snow
Problem Type
Wind Slab
Slab Thickness
10.0 inches
Vertical Fall
100ft
Slab Width
10.00ft
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Shooting cracks in wind slab north of Cooke

Date
Activity
Skiing

From obs: "We found up to a 6” deep wind slab producing shooting cracks at Goose Lake on a NW facing slope at 10500ft."

Region
Cooke City
Location (from list)
Goose Lake
Observer Name
Noah Mattes

Wind Slab Avalanche in Frazier Basin

Date
Activity
Skiing
Skier triggered wind slab on Northeast slope at 7,450 feet elevation. One skier was caught and carried roughly 10 feet before the slide came to a stop.
Region
Bridger Range
Location (from list)
Frazier Basin
Observer Name
R. Bechtold

South of Cooke City

Date
Activity
Skiing

Expected to find a different snowpack in the area southwest of Cooke/Silvergate, but once again we found deep (HS 235cm), strong, stable snow. 

Digging more than a foot or two into the snowpack is a chore. Even the north-facing snow below 8000' is incredibly dense and supportive. 

It seems like recent warm weather really helped consolidate the snowpack.

Don't take this good stability for granted - Even though the snowpack is generally stable, there is still trouble to be found in more consequential terrain. In one area, we did find some upside-down snow. It seemed stable, but in very steep terrain, even a small pocket releasing can cause trouble. We also witnessed a falling cornice today that washed some snow through rocks. Be aware of what's above you.

 

Region
Cooke City
Location (from list)
Abiathar Peak
Observer Name
Staples

Wind Loading in Ainger Lake Basin

Date
Activity
Snowboarding

Toured into Ainger Lake Basin in the Northern Bridgers today. From the Shafthouse Trailhead we could see debris from past wet snow avalanches coming from Ainger Peak and Hard Scrabble Peak area. The slide in Ainger Lake Basin must have been at least a few days old as the slide path and debris were covered in new snow from the last snowfall. The evidence of multiple slides we saw in Ainger Basin looked like they came from rocks shedding snow in the warm weather we've been having. Our objective was the middle couloir on Ainger Headwall. It was very windy in the basin. The slope above Ainger Lake Basin that we had to cross to get to the couloir was heavily wind loaded. We toured up and the snow felt stable so I decided to slowly skin out to see how the snow on this slope felt. It quickly became hollow sounding and we turned around and got a couple laps in for the day from there. Up high in the basin sun baked slopes that froze over night were very slick and hard with a couple inches of new snow on top making skinning difficult in places as well. 

Region
Bridger Range
Location (from list)
Frazier Basin
Observer Name
Connor Culver