This natural avalanche occurred on a slope that was wind drifted with cross-slope winds. It was a NE facing slope at 9,000 feet and likely ran over the weekend (2/20). Photo: GNFAC
Regional Conditions for Centennial Range
Bottom Line: With time the snowpack is adjusting to last week’s snow load and triggering avalanches is becoming more difficult. It’s scarier because the weak snow at the ground (depth hoar) has avalanched deep and wide on a few slopes.The recent deep slab natural activity in tandem with avalanche control at the ski area getting wide and deep slides makes me sit up straight and pay attention. Deep slabs are here to stay. These can be triggered from thinner areas (3 feet or less) by the weight of a person.
Primary Problem: Persistent Weak Layer
Snow Observations- Centennial Range & Lionhead
Centennial Range
Centennials - Idaho
Centennials: poor stability
I haven’t gotten a chance to write up my observations from the Centennial’s last Saturday but with this storm that’s occurring down there I thought it was important to reach out and let you know what I saw. The melt freeze crust from a few weeks ago and the rain crust from earlier in the season are still very present in the snow pack. There is about a 2 inch slab on top of the newest melt freeze crust that fractured on isolation. Should be a sporty couple days down in the centennials.
Full Snow Observation ReportCentennial Range
Centennials - Montana
Hellroaring
Observed 125 cm snow at 8200' on NE aspect. ECT showed propagation on each crust. South aspect at 7500' had ~65cm snow depth with similar crust but less reactivity. In general observed poor structure and poor strength everywhere.
Full Snow Observation ReportCentennial Range
CENTENNIAL RANGE
Tin Cup Pass-Mt. Jefferson-Centennials
Snow above the rain crust is starting to become more of a cohesive slab. No recent avalanches were observed.
Full Snow Observation Report
Cooke City
Republic Creek
Republic Creek, Woody Ridge Zone 2
We did a short tour yesterday in the middle of the storm into the Republic Creek drainage. Skies were overcast with light to heavy snow falling at times. Winds were gusting at times 60-80 mph, enough to blow you over if you weren't careful. Variable snowpack, wet and heavy down low until about 8800 feet then it got colder and less dense but was blowing around all over the place. The new snow was setting up very slabby in places with cracking expanding outward from the skin track and storm snow easily sliding at every kick turn. We did not dig a pit and instead opted to bail out at about 9400 feet and ski tighter trees back down to the creek bottom and home. The winds had stripped snow on the windward side with some larger drifts on the leeward side. However, in the basin, winds were coming from every direction at times. Not a very scientific observation but wanted to share what it was like in the storm up there yesterday. Caution really needs to be practiced as there are dense storm slabs sitting on large surface hoar/facets that had setup from the days of high pressure and winds may have deposited large amounts of snow in places.
Full Snow Observation ReportCentennial Range
CENTENNIAL RANGE
Tin Cup Pass-Mt. Jefferson-Centennials
Rain crust is still very present in the snowpack. Two natural slab avalanches on north aspect of Reas Peak, one from recent storm and one from previous storm. Photo is from a snowmobile triggered avalanche from 1/9/21, you can see the party and one of the members riding the adjacent slope. Snowpit attached as well.
Full Snow Observation Report
Centennial Range
Tin Cup Creek/Willow Creek Drainage
Yesterday I snowmobiled form the Keg Springs trailhead to Tin Cup Pass on Willow Creek. From the limited visibility we did not see any natural avalanche activity. We dug one pit on the Idaho side of the Centennials and found the total snow depth was 70cm and there were 2 distinct crusts in the snowpack and a fair amount of depth hoar. The pit profile was as follows:
70cm-55cm First Hardness
54cm-50cm 4 Finger
49cm-48cm Knife
47cm-25cm Fist (facets)
24cm-23cm Knife
22cm-0cm Fist (depth hoar)
Test Results: ECTN 12@49CM, ECTN 14@24CM
Full Snow Observation ReportCentennial Range
Centennials - Idaho
Island Park South West Aspect Tyler Creek Area
Seemingly unsafe snowpack here in island park. A few very firm crust layers. One facet layer near the base which propagated. Two crust layers, both knife hardness, were stacked in each other with a small amount of facets between them. This layer went on CTE 8. I wasn't able to attach it but I will send it separately. We weren't in avalanche terrain today so there were no other observations.
Full Snow Observation Report
Centennial Range
CENTENNIAL RANGE
Near Sawtelle Peak
Road cut south facing slope of 42 degrees, triggered intentionally by a guide, shows about 12 inches of windblown soft slab on top of a faceted layer (in this case more extreme due to aspect and inclination toward the sun) but was triggered only by chopping a hand into the snow a few times. This same faceted layer (the uppermost layer of a thick faceted layer of 1-2 fee) exists throughout the snowpack.
Also, the bottom-most layers of snow are very faceted and conditions have not occurred yet to set the snow for a base. Walking around your feet go right to the ground even in areas where snow is 2+ feet deep. There are many rock/tree hazards lurking under the soft snow because of this, two people in our group damaged their a-arms.
Full Snow Observation Report
Centennial Range
CENTENNIAL RANGE
Near Sawtelle Peak
Lower elevation plateau with low snow accumulation due to consistent wind-scouring, consists of about a foot of faceted snow with a dense wind-blown slab on top.
Full Snow Observation Report
Centennial Range
Ski Hill
Getting worse at Lionhead and Centennials
Both the Lionhead area and the nearby Centennial Range in Idaho have a similar snowpack. About 20-25" are on the ground consisting of weak, faceted, sugary snow. Riding is supportable, but we tiptoed around Lionhead because of rocks.Snow and wind are forecasted in the oming week. This snowpack will become unstable quickly. I expect to see cracking, whumpfs and recent avalanche activity. Small avalanhes on road cuts or creek banks are bulls-eye data that big avalanches are likely. Be careful, pay attention and stay clear of creeks and other terrain traps where even a small slide can be deadly. We made a video that outlines our concern which is posted on the Centennials page.
Full Snow Observation ReportAvalanche Activity- Centennial Range & Lionhead
Northern Madison
Beehive Basin
Splitboarder triggered, caught and killed in Beehive
Beehive Basin
HS-ARu-R4-D2.5-O
Elevation: 9,100
Aspect: SW
Coordinates: 45.3269, -111.3840
Caught: 2 ; Buried: 1; Killed: 1
More Avalanche Details
HS-ARu-R4-D2.5-O
Elevation: 9,100
Aspect: SW
Coordinates: 45.3269, -111.3840
Caught: 2 ; Buried: 1; Killed: 1
On February 14, 2021, two splitboarders triggered an avalanche in Beehive Basin north of Big Sky. They were skinning up the slope when they triggered the avalanche. Both members of the party were caught, but Boarder 1 was able to grab trees and not be buried. Boarder 2 was carried approximately 300 feet downslope where he hit a tree and was critically injured. He was partially buried, entangled around a tree with his head downhill. Boarder 1 heard his partner’s screams, called 911 and went to his aid. He administered first aid and worked to keep him warm and calm. Gallatin County Sheriff Search and Rescue in Big Sky (GCSAR) left the trailhead within 45 minutes of the 911 call, skied to the scene and began providing care. A GCSAR helicopter arrived soon afterward and the injured boarder was short hauled to Big Sky Fire Department and medical care. Boarder 2 died from his injuries that night. The avalanche was 300 feet wide, 500 feet vertical and averaged 2 feet deep. It broke on a layer of facets and near the ground. Read the full accident report here: https://www.mtavalanche.com/accident/21/02/16
More Avalanche Details
Southern Madison
Cabin Creek
Snowmobile triggered slides in Cabin Creek
Cabin Creek
SS-AMu-R3-D2-O
Coordinates: 44.8949, -111.2280
Caught: 0 ; Buried: 0
More Avalanche Details
SS-AMu-R3-D2-O
Coordinates: 44.8949, -111.2280
Caught: 0 ; Buried: 0
On 2/13/21 riders reported they triggered this avalanche, and remotely triggered two other slides. Nobody was injured. One partially buried.
More Avalanche Details
Lionhead Range
LIONHEAD AREA
Snowmobile triggered near Lionhead
LIONHEAD AREA
SS-AMu-R3-D2-I
Elevation: 8,000
Aspect: S
Coordinates: 44.7292, -111.3230
Caught: 0 ; Buried: 0
More Avalanche Details
SS-AMu-R3-D2-I
Elevation: 8,000
Aspect: S
Coordinates: 44.7292, -111.3230
Caught: 0 ; Buried: 0
Riders wrote that they triggerend an avalanche on a south facing slope in West Targhee Creek on 2/6/21. No one was caught.
More Avalanche Details
Photos- Centennial Range & Lionhead
Displaying 1 - 35
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This natural avalanche was likely triggered by a falling cornince in the last day or two. The slope is in the Wilderness and was seen from the boundary. Wind drifted snow is a concern in this area. Photo: GNFAC
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On 2/13/21 riders reported they triggered this avalanche, and remotely triggered two other slides. Nobody was injured. One partially buried.
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On 2/13/21 riders reported they triggered this avalanche, and remotely triggered two other slides. Nobody was injured. One partially buried.
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Sledders triggered this slide on 2/6/21 in West Targhee Creek near Lionhead. No one was caught.
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A snowmobiler triggered this avalanche on Monday (2/1/2021) at Lionhead. No one was caught. Photo: Anonymous
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A snowmobiler triggered this avalanche on Monday (2/1/2021) at Lionhead. No one was caught. Photo: Anonymous
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This small avalanche was below the corner of Lionhead peak. It was one of the smaller slides during the avalanche cycle that occurred 1/29 and 1/30. Photo: GNFAC
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The avalanche broke in the new snow, but stepped down into deeper layers (sugary facets) mid-path. This can occur when there are multiple weak layers in the snowpack. Photo: GNFAC
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Every path along the shoulder of Targhee Peak (Lionhead area) avalanched naturally during the storm 1/29 and 1/30. Photo: GNFAC
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This steep north facing slope avalanched about 3 weeks ago on depth hoar when a snowmobiler triggered it. It got reloaded with new snow and wind drifts and avalanched a second time! Photo: GNFAC
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This natural avalanche occured on a NE facing slope at 8600". It was 2' deep, 500' wide and 250' vertical. The avalanche broke on a thin layer of facets during the storm. SS-N-R3-D2-O. Photo: GNFAC
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On the north end of Lionhead Ridge is Airplane Bowl. The crown line extends across the entire bowl on the right with a separate avalanche on the left. Photo: GNFAC
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Take a close look at the picture and you'll see crowns from the far left to the far right of the photograph. Photo: GNFAC
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Many avalanches broke under the new snow and also deeper on facets. These natural slides occurred on 1/29 and 1/30. Photo: GNFAC
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Stepping out of my skis I sunk to the ground. The snowpack is weak and unsupportable. Large grains of sugary facets (depth hoar) make up the bottom third of the snowpack. Photo: GNFAC
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We saw this natural avalanche on 1/23/21. It likely occurred in the past week. SE aspect at 9,200', Photo: GNFAC
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A snowmobiler triggered slide on the east side of Lionhead Ridge to the north of Airplane Bowl. Photo: Photo: D. Haluptzok
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A snowmobiler triggered slide on the east side of Lionhead Ridge adjacent to a slope called Dead Tree Hill. Photo: D. Haluptzok
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From obs: "Rain crust is still very present in the snowpack. Two natural slab avalanches on north aspect of Reas Peak, one from recent storm and one from previous storm. Photo is from a snowmobile triggered avalanche from 1/9/21, you can see the party and one of the members riding the adjacent slope." Photo: C. Hericks
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We remotely triggered (from 30' away) this avalanche at Ski Hill in the Lionhead area. These are red-flags! Stay off of and out from under steep slopes until the avalanche conditions improve. Photo: GNFAC
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We triggered this avalanche from 50 feet away. We were walking on a low-angle slope, collapsed the slope, and where the pitch got steeper, we had an avalanche. This is an obvious sign of dangerous instability. If you are on steep slopes it is LIKELY that you will trigger an avalanche. Today, we triggered two avalanches. Photo: GNFAC
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A skier kicked off a larger than expected cornice as they skinned up the ridge on the W side of Beehive basin on Sunday (12/20/20).
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Doug intentionally triggered this wind-loaded sidehill. Weak, faceted snow broke under a 1' deep soft slab of windblown snow. Small avalanches like this are indicators of instability on bigger slopes. These conditions can be found throughout the southern Gallatin, southern Madison, Lionhead and Centennial Ranges. Photo: GNFAC
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We put up the Taylor Fork Weather station today. It measures wind direction and speed, RH, and temperature. Coupled with the Carrot Basin SNOTEL, this gives us a good idea on what is occurring in this range. Photo GNFAC
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Light wind created soft drifts of new, low density snow near the ridgeline in the Bridger Range. This wind slab easily cracked when touched with skis, 20 feet along the ridge and 5-10 feet down, but didn't slide. This is a sign drifts will be unstable as they grow with more snow and wind. Photo: GNFAC
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From IG post: "Weak and thin snowpack. A little sluff was all it took to entrain the whole season’s snowpack. S. Madison ~9000’ east facing" Photo: @vt.to.mt
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From IG post: "Weak and thin snowpack. A little sluff was all it took to entrain the whole season’s snowpack. S. Madison ~9000’ east facing" Photo: @vt.to.mt
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We found a thick layer of surface hoar (1-2cm) on top of the snowpack at Lionhead Ridge on 11/24/20. Below that layer the snowpack was faceted and weak. This will be an unstable foundation for future storms. Photo: GNFAC
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Watch the video HERE!
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The BBWC (Bridger Bowl Wind Cloud) on Tuesday 10/27 accompanied 50-60 mph gusts. This strong wind drifted recent snow into slabs that could avalanche on steep slopes. Early season snow means we need to be thinking about and managing avalanche hazard when we travel in the mountains. Photo: GNFAC
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Backcountry.com did a social media survey and found that many of us could use an avalanche class. Don't hesitate to sign up for one. Even a one-hour avalanche awareness class is a great place to start. Check out our Education Calendar for an expanding list of classes being offered in southwest Montana. Many are free.
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Wind was blowing and drifting recent snow in the Bridger Range the morning of October 15th. Photo: B. VandenBos
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Snow on Lone Mtn. on the morning of October 14th. Photo: B. VandenBos
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By morning of October 11 most mountain ranges were white at the higher elevations. This picture of Saddle Peak was taken from Stone Creek up Bridger Canyon. About .6-.8" of precipitation fell throughout southwest Montana. The Fisher Creek Snotel outside of Cooke City shows 6" of snow fell at 9,100 feet. Only time will tell what melts and what sticks around, but it sure is a good sign! Photo: GNFAC
Videos- Centennial Range & Lionhead
Live Webcam Images
Weather Forecast- Centennial Range
Extended Forecast for
10 Miles ESE Lakeview MT
Winter Weather Advisory February 25, 02:00pm until February 26, 09:00pm
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Today
Slight Chance
Snow then
Snow Likely
and Patchy
Blowing SnowHigh: 23 °F
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Tonight
Snow Likely
Low: 6 °F
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Friday
Snow and
Patchy
Blowing SnowHigh: 16 °F
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Friday
NightSnow Likely
and Patchy
Blowing Snow
then Chance
SnowLow: 3 °F
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Saturday
Snow Likely
High: 16 °F
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Saturday
Night
Partly Cloudy
Low: -1 °F
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Sunday
Partly Sunny
High: 16 °F
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Sunday
NightPartly Cloudy
Low: 6 °F
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Monday
Slight Chance
SnowHigh: 24 °F
The Last Word
The US has reached 32 avalanche fatalities this season. With a lot of the avalanche season left we may reach 40 avalanche deaths for the first time since the winter of 1925-26. This is not a total we want to reach. A compilation of all avalanche fatality information can be found here.