Regional Conditions for Lionhead Range

as of 5:00 am
Today-1″ | N/A
Apr 24 -1″ | N/A
Apr 23 0″ | N/A
8775′     /00 at :
- mph
Gusts mph
7750′   04/25 at 12:00
48℉
72″ Depth
Bottom Line: This week expect classic spring snowpack conditions, with great variability throughout the day and between aspect and elevation. Ideally the snowpack will be mostly frozen and stable in the morning, and then it will inevitably soften and lose strength through the day. Be diligent with route finding and snowpack assessment, anticipate changing conditions, pay attention to unexpected findings, and have a safe route to bail at any time. Consider terrain you will have to travel across or underneath later in the day when natural wet slides may occur or be easier to trigger. See our forecast page for general spring snowpack and travel advice.

Past 5 Days

Wed Apr 10

None
Fri Apr 12

None
Mon Apr 15

None
Fri Apr 19

None
Mon Apr 22

None

Avalanche Activity- Lionhead Range

Out of Advisory Area
Emigrant Peak
Wet slab and large wet loose near Emigrant
Incident details include images
Emigrant Peak
WS-N-R3-D2.5-I
Elevation: 10,000
Aspect: NE
Coordinates: 45.2648, -110.7010
Caught: 0 ; Buried: 0

From e-mail: "recent wet slab by Emigrant peak as well as a large wet loose (very similar avy activity noted across the valley, and i would guess similar activity in some of the fx zones).  Wet slab 3-5’ crown estimation, all look connected/pulled out upon one another,..."


More Avalanche Details

Photos- Lionhead Range

Displaying 1 - 40 of 4.6116860184274E+18
  • Observed 4/20/19. Crown estimated 3-5' deep. Above freezing temperatures, sunshine and rain created a wet and weak snowpack. Photo: G. Antonioli

  • Observed 4/20/19. Crown estimated 3-5' deep. Above freezing temperatures, sunshine and rain created a wet and weak snowpack. Photo: G. Antonioli

  • Below 3-5" of new snow there is a supportable frozen crust on top of a wet snowpack on most slopes. Avalanches are mostly confined to the new snow on top of this crust (wet loose, dry loose, wind slabs). However, where the snowpack did not freeze below the new snow, or when this crust melts, deeper wet slides are possible. Photo: GNFAC

  • Snowmobile-triggered slide near Fairy Lake on Saturday (3/30). New snow was drifted into small wind slabs that may remain reactive in isolated areas.  Photo: P. Cronin

  • Outside Cooke City up Zimmer Creek, a skier spotted this cornice fall which triggered a small pocket down low. Photo: F. Madsen

  • Many wet loose and wet slab avalanches were seen near Zimmer Creek (north of Cooke City) on south and east aspects. Temperatures were warm at 10,000 feet. Photo: F. Madsen

  • This photo near Lionhead, is indicative of the wet loose avalanches we are seeing on many low elevation, south facing slopes throughout our advisory area. Daytime temperatures near 50F will make avalanches like this more frequent and widespread in the coming days.

  • 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

Videos- Lionhead Range

Weather Forecast Lionhead Range

Extended Forecast for

10 Miles WNW West Yellowstone MT

  • This
    Afternoon

    This Afternoon: Sunny, with a high near 46. Southwest wind 10 to 15 mph, with gusts as high as 23 mph.

    Sunny

    High: 46 °F

  • Tonight

    Tonight: A 20 percent chance of snow showers after 5am.  Partly cloudy, with a low around 32. Southwest wind 10 to 15 mph, with gusts as high as 23 mph.

    Partly Cloudy
    then Slight
    Chance Snow
    Showers

    Low: 32 °F

  • Friday

    Friday: Rain and snow showers, becoming all snow after 4pm. Some thunder is also possible.  High near 41. Breezy, with a southwest wind 13 to 18 mph increasing to 23 to 28 mph in the afternoon. Winds could gust as high as 40 mph.  Chance of precipitation is 100%. Little or no snow accumulation expected.

    Rain/Snow
    Likely then
    Rain/Snow and
    Breezy

    High: 41 °F

  • Friday
    Night

    Friday Night: A 20 percent chance of snow showers before midnight. Some thunder is also possible.  Partly cloudy, with a low around 24. Windy, with a west northwest wind 21 to 31 mph becoming southwest 10 to 20 mph after midnight. Winds could gust as high as 34 mph.

    Slight Chance
    Snow Showers
    and Windy
    then Mostly
    Clear

    Low: 24 °F

  • Saturday

    Saturday: Mostly sunny, with a high near 39. Windy, with a light west southwest wind becoming southwest 31 to 36 mph in the afternoon. Winds could gust as high as 39 mph.

    Sunny then
    Partly Sunny
    and Windy

    High: 39 °F

  • Saturday
    Night

    Saturday Night: A slight chance of snow showers before midnight, then a chance of snow after midnight.  Mostly cloudy, with a low around 20. Windy.  Chance of precipitation is 30%. New snow accumulation of less than a half inch possible.

    Chance Snow
    and Windy

    Low: 20 °F

  • Sunday

    Sunday: A 40 percent chance of snow.  Partly sunny, with a high near 31. New snow accumulation of less than a half inch possible.

    Chance Snow

    High: 31 °F

  • Sunday
    Night

    Sunday Night: A slight chance of snow.  Mostly cloudy, with a low around 19.

    Slight Chance
    Snow

    Low: 19 °F

  • Monday

    Monday: A chance of snow, mainly after noon.  Partly sunny, with a high near 31. Blustery.

    Chance Snow
    and Blustery

    High: 31 °F

The Last Word

For more spring travel advice see this article from our GNFAC forecaster blog.


  <<  This is the most recent forecast.