Regional Conditions for Lionhead Range

as of 5:00 am
Mar 190″ | 15-30 NW
Mar 18 0″ | 5-18 N
Mar 17 0″ | 0-15 SW
8775′     3/20 at 1:00
31 ℉
NW - 7 mph
Gusts 10 mph
7750′   03/20 at 1:00
21℉
79″ Depth
Bottom Line: Avalanches are unlikely today. The combination of warm days and below freezing temperatures at night has been good for stability. Small wet loose avalanches could run on crusts as they break down this afternoon. A week out from the last snowfall triggering a dry snow avalanche is unlikely but not impossible. Keep up good travel practices to minimize the consequences if you do trigger a slide.

Past 5 Days

Fri Mar 15

Low
Sat Mar 16

Low
Sun Mar 17

Low
Mon Mar 18

Low
Tue Mar 19

Low

Avalanche Activity- Lionhead Range

Cooke City
COOKE CITY
Avalanches in new snow in Cooke City
Incident details include images
COOKE CITY
SS
Caught: 0 ; Buried: 0

These are observations from Doug Chabot's field trip on 3/8, Friday:

  1. One slide was triggered on a steep (40 deg) southeast facing slope at Round Lake outside Cooke City. It failed 8" deep on a layer of graupel and small facets. An adjacent hill slid at the same depth beforehand. This layer is not on most slopes, but as this slide shows it is on some. Doug was in the area and dug a pit in the crown soon after it was triggered.
  2. A slide under the cornice on the northeast face of Abundance looked to be 1 foot deep and 200' wide.
  3. A snowboarder reported triggering an 8" deep slab on the south face of Scotch Bonnett in one of the Rasta's.

More Avalanche Details
Northern Gallatin
Mt Blackmore
Skier triggered avalanche on Mt. Blackmore
Incident details include images
Mt Blackmore
SS-ASu-R2-D1.5-I
Aspect: NE
Coordinates: 45.4455, -111.0040
Caught: 0 ; Buried: 0

From an email:

"I’d like to report an avalanche incident that occurred today, 3/6, around 2 PM on the NE face of Mt. Blackmore in the Hyalite Canyon area. On the approach, I dug a pit at 9400’ and found a very stable and deep snowpack, with a somewhat definite weak layer in between high and medium density snow about 8” deep. The layer did not slide or propagate in an extended column pit test, so my partner and I decided do ski the direct line from the summit. I skied first, making a ski cut just below the ridge line that did not result in any sloughing. I skied the line without mishap. My partner followed, traversing onto a shallow, steep pocket, releasing the avalanche. It propagated down and out in both directions, resulting in a v-shaped crown about 100’ across and 8-12” deep. The slide ran from around 9800’ to 9400’. My partner was not caught and was able to traverse out and ski down safely."


More Avalanche Details
Southern Madison
Taylor Fork
Natural Avalanches in the Taylor Fork area
Incident details include images
Taylor Fork
SS-N-R2-D2-O
Coordinates: 44.9641, -111.3170
Caught: 0 ; Buried: 0

A snowmobiler sent in a photo of multiple natural avalanches near Woodward Mtn. He also reported large avalanches near Pika Point and Skyline Ridge that failed at the ground. Photos: P. Honsinger


More Avalanche Details

Photos- Lionhead Range

Displaying 1 - 40 of 4.61168601843E+18
  • Low angle metal roofs have heavy, thick slabs of snow that built up during persistent cold temperatures. These slabs will slide during warm temperatures. Be on the lookout for overhead hazard and be cautious where you walk or park your car during warm sunny days. An additional urban hazard are large icicles are that will break during warm days. Photo: A. Schauer

  • This slide was triggered on a steep (40 deg) southeast facing slope at Round Lake outside Cooke City. It failed 8" deep on a layer of graupel and small facets. An adjacent hill slid at the same depth beforehand. This layer is not on most slopes, but as this slide shows it is on some. Doug was in the area and dug a pit in the crown soon after it was triggered. Photo: J. Fritz

  • This slide on the NE face of Blackmore was triggered by the second skier. It was 8-12" deep and 100' wide and likely failed on small faceted crystals underneath the new snow. No one was caught. Going one at a time was good travel behavior that can save our lives when things go wrong.

  • This picture of the large avalanche on Lionhead Ridge was taken from Two Top Mtn to the south. Photo: P. Smith

  • The crown on this slide ranges from 4-6' deep. It occurred on a heavily wind loaded slope and broke on facets near the ground. It's a clear reminder that large avalanches are possible in the mountains near West Yellowstone. 

  • This slide occurred in the Lionhead area near West Yellowstone. It broke 4-6' deep, failing on facets near the ground. It's unknown if it was triggered by a natural cornice failure or by a snowmobiler. Either way, it's a clear reminder that large avalanches are possible in the mountains near West Yellowstone. 

  • This snowmobile was fully buried, along with its rider on February 7th, 2019, in the Centennial Range.

  • Photo of the snowmobile triggered slide that fully buried a rider on February 7th, 2019.

  • A large snowmobile triggered avalanche in the Gravelly Range (Outside of advisory area) on February 10th, 2019.

    From email: "One rider was involved in the incident and was fortunate to be on the upper left side of the bowl when he saw the slide start. ... the crown was about 325 wide and varied in depth from 1 to 4 or 5 feet.  The ridge line was wind loaded and this was an issue we had discussed as a group and wanted to avoid.  We had read the reports for the day and knew that wind loading as well as a persistent week layer were both concerns. .... The rider involved entered the area from around where the road switchbacked and did not realize what was above him due to reduced visibility."

  • This avalanche broke on weak snow in the lower 1/3 of the snowpack after a storm dropped 2-3' of heavy snow between 2/3 and 2/5/19. Photo: GNFAC

  • Multiple large avalanches occurred in the Lionhead area near West Yellowstone after 2-3’ of heavy snow earlier this week. Photo: GNFAC

  • This avalanche was triggered by snowmobilers on 2/6. 2-3’ of heavy snow earlier this week fell on a weak snowpack making large avalanches possible. Photo: GNFAC

  • This avalanche was triggered by snowmobilers on 2/6. 2-3’ of heavy snow earlier this week fell on a weak snowpack making large avalanches possible. Photo: GNFAC

  • From an email, "Observed this large avalanche while driving north from Jackson Hole today.  (on the E, NE aspect of Sawtell Peak, in the Centennial Mountains)"

    Likely released in the last day or so with the Avalanche Warnings on Sun, Mon and Tuesday. Photo: B. Fredlund

  • Snowmobilers in the Lionhead area got unstable test results, easily propagating fractures in ECT tests on a weak layer buried about 50 cm deep. Photo: J. Norlander

  • This photo was taken by a FS snow ranger on Feb 1st. These avalanches likely occurred towards the end of a period of steady snowfall from Jan 16th to 28th. From e-mail: "The Reas Peak area had 7 slides that I could see from the bottom of the drainage, most of them looked to have occurred with the last storm and had a northerly influence to their aspect. The largest and most recent slide I included in the [above photo], Reas Peak is the highest peak on the left in the photo and the slide path is on a NE aspect. If you look close at the photo you can see a 2-3’ crown on the far left side of the frame on the north aspect of Reas from another slide." Photo: C. Hericks

  • This photo of an avalanche on the north side of Reas Peak was taken by a FS snow ranger on Friday, Feb 1. It likely occurred towards the end of a period of steady snowfall from January 16th to 28th. Photo: C. Hericks

  • Mount Jefferson (just north of Reas Peak) is the peak in the background. Nasty avalanche on persistent weak layer in the foreground. Photo: B. VandenBos

  • Large avalanche on Bald Peak in the Lionhead area near West Yellowstone. Photo: B. VandenBos

  • A very deep natural avalanche was observed on Sheep Mountain, on January 28th. 

    From email: "This was southern facing slope of sheep mountain... Crown was at least 8’... very heavy wind loading."

    Photo: H. Menssen

  • Cracking and collapsing on a 31-degree slope near the Lionshead area down south. The slab was 3-4' deep, and the slope was on the verge of being steep enough to avalanche. From the email: " fractured about 20’x10’ area initially, maybe 3-4’ deep. We got off the hill and it continued to fracture in bigger spots but did not slide more than a foot total." Photo: S. Thompson

  • Crown of avalanche that was triggered by a group of four skiers. Two were partially buried (1 injured, 1 killed) on 1/25/19. They were all ascending and near the top of the path when the avalanche broke. The top two skiers held onto trees as the avalanche pushed by them. Photo: GNFAC

  • Overview of avalanche path where a group of four skiers were caught, and two were partially buried (1 injured, 1 killed) on 1/25/19. Crown is marked by black line and location of partial burial/deceased is tip of red arrow. The other partially buried skier was 200' lower. They were all ascending and near the top of the path when the avalanche broke. The top two skiers held onto trees as the avalanche pushed by them. Photo: GNFAC

  • From an email:

    "...was riding with a group near the Two Top area and remotely triggered this slide as rode past this drainage on the top of the ridge. It was a north facing wind loaded slope in the 38 degree slope range. It broke about 12 inches deep and looked like it was from the last snow/wind loading." Photo: J. Norlander

  • From facebook: "natural avalanche down near reynolds pass. West facing slope, it faces hwy 87 and is named mile Creek trail by usfs. No snowmobiling and haven't ever seen anyone ski it."

  • This graph shows snow water equivalent (SWE) by date at the primary SNOTEL sites that we use in the GNFAC region. From October 1st, 2018 to January 12th, 2019. Steeper lines indicate bigger storms and flatter lines indicate periods of little to no snow. A large storm at the beginning of Novermber laid down a 1-3 foot base. Relatively dry and cold weather through November caused much of that snow to become weak. This weak snow was buried by a series of storms. Avalanches were seen during and following many of these storms. During dry weather between storms, more weak layers formed on the surface of the snowpack and were subsequently buried. (Graph created by GNFAC from NRCS provisional data).

  • One of many avalanches that broke during the last week's avalanche cycle at Lionhead. Natural and snowmobile triggered slides were reported between 1/7 and 1/9/19. On 1/6-1/7 the area got a foot of heavy snow followed by strong winds. This loaded an unstable snowpack that is poorly supported by 1.5' of sugary snow on the ground. Avalanches broke 2-3 feet deep on this weak snow, and propagated relatively wide. Photo: GNFAC

  • One of many avalanches that broke during the last week's avalanche cycle at Lionhead. Natural and snowmobile triggered slides were reported between 1/7 and 1/9. On 1/6-1/7 the area got a foot of heavy snow followed by strong winds. This loaded an unstable snowpack that is poorly supported by 1.5' of sugary snow on the ground. Avalanches broke 2-3 feet deep on this weak snow, and propagated relatively wide. Photo: GNFAC

  • A snowmobile triggered avalanche that broke during the last week's avalanche cycle at Lionhead. Multiple (5+) natural and snowmobile triggered slides were reported between 1/7 and 1/9. On 1/6-1/7 the area got a foot of heavy snow followed by strong winds. This loaded an unstable snowpack that is poorly supported by 1.5' of sugary snow on the ground. Avalanches broke 2-3 feet deep on this weak snow, and propagated relatively wide. Photo: GNFAC

  • A snowmobile triggered avalanche that broke during the last week's avalanche cycle at Lionhead. Multiple (5+) Natural and snowmobile triggered slides were reported between 1/7 and 1/9. On 1/6-1/7 the area got a foot of heavy snow followed by strong winds. This loaded an unstable snowpack that is poorly supported by 1.5' of sugary snow on the ground. Avalanches broke 2-3 feet deep on this weak snow, and propagated relatively wide. Photo: GNFAC

  • A snowmobile triggered avalanche that broke during the last week's avalanche cycle at Lionhead. Multiple (5+) Natural and snowmobile triggered slides were reported between 1/7 and 1/9. On 1/6-1/7 the area got a foot of heavy snow followed by strong winds. This loaded an unstable snowpack that is poorly supported by 1.5' of sugary snow on the ground. Avalanches broke 2-3 feet deep on this weak snow, and propagated relatively wide. Photo: GNFAC

  • In Cabin Creek (1/10/19) we found a recently buried layer of surface hoar as well as the weak, sugary snow that makes up the bottom 1.5' of the snowpack in the southern ranges. Avalanches are possible to trigger on the sugary facets near the ground. Both of these weak layers will persist and cause avalanches when we get more snow and wind loading. Photo: GNFAC

  • February 2, King and Queen of the Ridge at Bridger Bowl (fundraiser). Register with Bridger to hike in the event, and create a pledge page to raise funds with your Ridge laps.

  • A snowmobiler triggered a slide in Lionhead on Tuesday, January 8. Photo: D. Mintus

  • A sledder remote triggered several slides from the bottom of a south facing slope in the Centennial Range, Hell Roaring Creek. Photo: B. Marsh

  • A sledder remote triggered several slides from the bottom of a south facing slope in the Centennial Range, Hell Roaring Creek. Photo: B. Marsh

Videos- Lionhead Range

Weather Forecast Lionhead Range

Extended Forecast for

10 Miles WNW West Yellowstone MT

  • Overnight

    Overnight: Clear, with a low around 18. Northeast wind around 6 mph.

    Clear

    Low: 18 °F

  • Wednesday

    Wednesday: Sunny, with a high near 48. East northeast wind around 6 mph becoming light and variable.

    Sunny

    High: 48 °F

  • Wednesday
    Night

    Wednesday Night: Clear, with a low around 22. Light and variable wind becoming east northeast 5 to 7 mph after midnight.

    Clear

    Low: 22 °F

  • Thursday

    Thursday: Sunny, with a high near 50. East wind 7 to 14 mph.

    Sunny

    High: 50 °F

  • Thursday
    Night

    Thursday Night: Partly cloudy, with a low around 24. East wind 9 to 14 mph.

    Partly Cloudy

    Low: 24 °F

  • Friday

    Friday: A 30 percent chance of rain after noon.  Partly sunny, with a high near 49.

    Mostly Sunny
    then Chance
    Rain

    High: 49 °F

  • Friday
    Night

    Friday Night: Rain likely before 7pm, then snow likely.  Mostly cloudy, with a low around 27. Chance of precipitation is 60%. New snow accumulation of 1 to 2 inches possible.

    Rain/Snow
    Likely then
    Chance Snow

    Low: 27 °F

  • Saturday

    Saturday: Snow likely.  Mostly cloudy, with a high near 32.

    Snow Likely

    High: 32 °F

  • Saturday
    Night

    Saturday Night: A chance of snow.  Cloudy, with a low around 26.

    Chance Snow

    Low: 26 °F

The Last Word

Spring is here and wet snow avalanches are becoming a daily concern. Anticipate decreasing stability while forming a travel plan. This article from Backcountry Magazine highlights some things look for that indicate when it is time to turn around.