22-23

Lionhead

Date
Activity
Snowmobiling

We rode back to the recommended wilderness boundary through Denny Creek, Watkins Creek, etc. We saw the avalanche triggered by a ground of riders around the corner from Airplane Bowl. It was 150’ wide x 4-5’ deep and 150-200’ vertical. The debris was piled 5-6’ deep, certainly deep enough to bury or injury a rider or skier. This was a close call.

We observed several recent storm and wind slab avalanches from Lionhead Ridge but not other deep slab avalanches. The snowpack structure is similar to what we have seen in the past rides to the area, a 3” thick layer of facets 1-2’ deep and facets buried near the base of the snowpack. Avalanches are becoming less likely without new snow, but the structure will keep the danger heightened for a while.

Looking forward, there was surface hoar covering most slopes, and it is supposed to snow lightly through the week. We will be watching this for a possible new layer of concern.

 

Region
Lionhead Range
Location (from list)
LIONHEAD AREA
Observer Name
Dave Zinn

Natural slides near Cabin Creek

Cabin Creek
Southern Madison
Code
R1-D1
Latitude
44.89490
Longitude
-111.22800
Notes

Two natural avalanches in the Cabin Creek area.

From instagram: "Right off the trail at tepee creek just before the cabin. A natural slide about 2ft crown"

From email: "I came across this older avalanche yesterday when I was guiding a group in the Kirkwood area, it’s an area in the Cabin Creek drainage. It looked to be an older natural slide probably just after the last storm cycle a few days to almost a week ago now. North, North East Aspect. Approximately 39 degree slope (Because of a creek with open water just below the slide, I couldn’t get close enough to accurately measure the slope)". 

Number of slides
2
Number caught
0
Number buried
0
R size
1
D size
1
Slab Thickness
24.0 inches
Vertical Fall
20ft
Slab Width
40.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Natural slide in Tepee

Date
Activity
Snowmobiling

From instagram: "Right off the trail at tepee creek just before the cabin. A natural slide about 2ft crown"

Region
Southern Madison
Location (from list)
Cabin Creek
Observer Name
Matt Neu

Mt Ellis

Date
Activity
Skiing

The snowpack structure has deteriorated on Ellis since the last time I was there a couple of weeks ago, but without loading, it remains generally stable. I am less optimistic about future stability. All slopes were covered by a layer of surface hoar and near-surface facets. Light winds will do little today to disrupt the surface snow. Hopefully we get some wind that beats this layer up a bit before it gets buried. 

We felt that finding instability was unlikely today with ECTXs and ECTNs in the 20s in both our pits.

 

Region
Northern Gallatin
Location (from list)
Mt Ellis
Observer Name
Dave Zinn

Small snowmobile triggered slide on Buck Ridge

Buck Ridge
Northern Madison
Code
SS-AM-R1-D1
Elevation
9400
Aspect
NE
Latitude
45.17190
Longitude
-111.38000
Notes

Small snowmobile triggered slide (~1ft deep and ~20x20 ft) at the head of Muddy Creek (NE Aspect, 9400 ft) off Buck Ridge. Looks like it was likely triggered on Sunday (Jan 1st) in a shallow spot near rocks.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Snowmobile
R size
1
D size
1
Slab Thickness
12.0 inches
Vertical Fall
20ft
Slab Width
20.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Snowmobile triggered slide (~1ft deep and ~20x20 ft) at the head of Muddy Creek (NE Aspect, 9400 ft) off Buck Ridge. Looks like it was likely triggered on Sunday (Jan 1st) in a shallow spot near rocks. Photo: GNFAC (1/3/2023)

Northern Madison, 2023-01-03

Widespread surface hoar and small avalanche

Date
Activity
Snowmobiling

Rode through 1st, 2nd, & 3rd Yellowmules, into the heads of McAtee, Muddy, and Bear Creeks. Saw a small snowmobile triggered slide (~1ft deep and ~20x20 ft) at the head of Muddy Creek (NE Aspect, 9400 ft). Looks like it was likely triggered on Sunday (Jan 1st) in a shallow spot near rocks. No other avalanches or signs of instability. Dug on NE and SE aspects around 9400 ft (HS100-140) and found F+ to 4F facets in the bottom 2/3rd of the snowpack, but got ECTN21 and ECTX. 

Widespread big crystals of surface hoar (feathers around 1 cm in size). We will be watching to see if it is buried as it is potentially our next weak layer of concern.

Region
Northern Madison
Location (from list)
Buck Ridge
Observer Name
Ian Hoyer