Trip Planning for Cooke City Area

as of 5:00 am

Today	1″ \| 15-50 NW
Dec 8	2″ \| 10-37 SW
Dec 7	0″ \| 10-21 NW

Lulu Pass Weather Station

10020′ 12/09 at 17:00

5.8℉
NW - 18mph
Gusts 24 mph

Fisher Creek SNOTEL Site

9100′ 12/09 at 18:00

10℉
23″ Depth

Full Forecast

Primary Problem: Wind Slab

Bottom Line: Human-triggered avalanches in fresh drifts of wind-loaded snow near ridgelines and in steep gullies are possible. With storm totals ranging from 2-4”, wind slabs will be 4-8” thick and relatively small. Seek out slopes sheltered from recent wind-loading where human-triggered avalanches are unlikely. Carry rescue equipment, dig to assess for instability related to buried weak layers before committing to steep slopes and travel one at a time with someone in safe position for rescue when traveling in and around avalanche terrain.

Past 5 Days

Thu Dec 5

Moderate

Fri Dec 6

Low

Sat Dec 7

Low

Sun Dec 8

Moderate

Today

Moderate

Relevant Avalanche Activity

2024-12-02

Cooke City

Lulu Pass

Wet Loose at Lulu Pass

Lulu Pass
WL-N-R2-D1-S
Elevation: 10,000
Aspect: S
Coordinates: 45.0709, -109.9580
Caught: 0 ; Buried: 0

Natural loose wet avalanche

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Wet Loose avalanche at Lulu

2024-11-28

Cooke City

Henderson Mountain

Old wind slab Henderson

Henderson Mountain
HS-NC-R2-D1.5-G
Elevation: 10,100
Aspect: NE
Coordinates: 45.0524, -109.9450
Caught: 0 ; Buried: 0

Hard wind slab likely on facets happened naturally maybe last week around Thanksgiving or just after. It is typically heavily wind loaded spot and was probably triggered by cornice fall.

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Old wind slab avalanche on Henderson

2024-11-22

Cooke City

Henderson Mountain

Localized cracking and collapsing on Mt. Henderson

Henderson Mountain
Elevation: 9,700
Aspect: SW
Coordinates: 45.0524, -109.9450
Caught: 0 ; Buried: 0

Localized collapsing and cracking yesterday on the upper slopes of Mt. Henderson, SW aspects. HS ranged from about 30-75cms.

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Relevant Photos

Displaying 1 - 21

Snowpack on Henderson Bench

Snowpack on Henderson Bench on NE facing slope
Wet Loose avalanche at Lulu

Wet Loose avalanche at Lulu on South facing slope
Old wind slab avalanche on Henderson

Old wind slab avalanche on Henderson that likely failed on old facets near the ground after heavy wind loading. NE facing at about 10,100 ft.
1cm surf hoar at Lulu

1cm surf hoar at Lulu
Snowpit @ 9410 , NNW Aspect

"At 9410ft, NNW aspect, 10 degree slope, we found HS 75cm. The general structure seems right side up. There are facets at the bottom 20cm or so, but they are wet, and seem to be rounding. An ECT gave us ECTN20 at 40cm down." Photo: N. Mattes
E facing snow at 8100 ft Cabin Ck

WE facing snow at 8100 ft Cabin Ck
SE facing snow Cabin Creek

SE facing snow Cabin Creek
N facing snow Cabin Creek

N facing snow Cabin Creek, 9000 ft
Large Avalanche on facets triggered by Big Sky patrol

Big Sky Ski Patrol triggered this avalanche during mitigation work in The Wave on 11/26/24... "2-3' deep on an ice crust just above the ground with a 2# shot in the Upper rodeo. Volume was limited as most of the snow was loaded just underneath the cornice, but still produced a sizeable size 2... Other paths in the Lenin region ran meaty wind slabs, full track with no significant step downs." Photo: BSSP
Big Sky cracking of snowpack

Cracking on old, faceted, October snow hundreds of feet long. North facing near treeline. Photo: BSSP
Big Sky triggered avalanche

Intentional, human-triggered avalanche by a ski patrol breaking at the ground on a north facing slope near treeline. Photo: BSSP
West of the main boulder looking south towards the pyramid.

View looking south towards the Pyramid. Photo: J. Negri
Goose creek looking north.

Photo: J. Negri
Cross loading on Sheep Mountain

Evidence of cross loading on Sheep Mountain. Photo: J. Negri
Snowpit at Bridger

Snowpit at Bridger Bowl on 11/5. Photo: B. VandenBos
Cracking in recent hard wind slab

From e-mail: "Photo attached from near top of hyalite peak, 11/2. Cracking in recent hard wind slab, I had to really jump hard to make this. Walked on many other hard slabs that were well bonded. Highly variable snowpack. I think you'd be most likely to get into trouble by popping out a small hard slab pocket like this and getting magic carpeted into some thinly covered terrain." Photo: B. VandenBos
New snow in Cooke City on Sinclair webcam, Nov 1

Screenshots of webcams throughout the forecast area show new snow and snow cover on November 1.
Minor Faceting in At Spanish Peaks Resort

From obs: "1-3 mm faceting in front of the Montage. Clear skys and mid 20 temps"
Fresh Snow in Big Sky

On October 17, rain turned to snow and blanketed the mountains of southwest Montana with a fresh coat of snow. Photo: Yellowstone Club Webcam
Bridger Bowl Ridge Webcam

On October 17, rain turned to snow and blanketed the mountains of southwest Montana with a fresh coat of snow. Photo: Bridger Bowl Webcams
Powder Blast 2024 - October 25

The 26th annual fundraiser for the Friends of the GNFAC is October 25 at the Emerson Cultural Center. More info and tickets at: https://events.eventgroove.com/event/Powder-Blast-2024-101627