Regional Conditions for Centennial Range

as of 5:00 am
Today0″ | 5-18 N
Mar 17 0″ | 0-15 SW
Mar 16 0″ | 5-10 W
8775′     3/18 at 8:00
21 ℉
NW - 8 mph
Gusts 15 mph
7750′   03/18 at 9:00
31℉
101″ Depth
Bottom Line: Today the snowpack is generally stable and avalanches are unlikely. Sunny slopes have a stable, frozen crust on the surface which will be slow to melt, and wet loose avalanches will be minimal. Small wet loose avalanches are possible near steep, sunny rock outcrops. Large cornices can break naturally. Minimize or avoid travel on slopes below cornices. Look out for small fresh wind slabs if you see blowing snow along ridgelines. Carefully assess the snowpack and terrain for possible isolated instabilities.

Snow Observations- Centennial Range & Lionhead

Centennial Range
Centennials - Montana
Hellroaring Basin / Mt. Nemesis

We found a 2.85m settled base at roughly 7,000’ elevation base camp of Hellroaring Powder Guides.
The temps have been cold, but warming into the high 20s, low 30s during sunny periods.
A sample snowpit showed a weak layer of concer at about 50-60cm below the surface, made of very small facets.
However, an ECT was non-reactive. No signs of recent avalanches in the basin were present. Hower, some debris piles from older slides were apparent in the larger runout zones on Mt. Nemesis.

Full Snow Observation Report
Centennial Range
Hellroaring Creek
Hellroaring
Incident details include images

Widespred slide activity from the last storm cycle, e.g. 2/14-2/18 ranging from E-NE to W. Aspects all elevations, creek bottoms slid at 7000' and peaks slide at 9800'. DEEP crownlines. From a dist. 4'-6', mostly in wind loaded terrain, micro-ridges, and corniced areas.

Full Snow Observation Report
Lionhead Range
Two Top
Twin Creek Snowmobile Trail (ID) Closed for Avalanche Danger

Liz Davey, Island Park District Ranger on the Caribou-Targhee NF, said that the Twin Creek Snowmobile Trail is closed because of avalanche danger!!

Full Snow Observation Report
Centennial Range
Hellroaring Creek
Hellroaring Hut Area

***This report was submitted by a guest from a recent hut trip***

2-13-19 0630Hrs 7700’ at hut, SW winds, mod. 14F, S2 Precip.

1300Hrs Test Pit at top of Pussyfoot, 200 degrees, slope angle 20, 7700 elevation, snowing S2, winds SW and variable and Mod, 14F: 205HS, CT 21 down 61cm; CT 23 down 75; CT 30 down 86. ECTX. We found a dense consolidated layer(k hardness) 12”++ deep, down 120CM and stopped digging there. Storm/wind slab gained energy around 1500Hrs. Many different layers in the top 60CM of the new snow, none of them particularly concerning.

On 2-14-19 0700Hrs At the hut: ,23F, and S2 for 24hrs past, with an estimated 18-24 HN24. SW winds Mod, variable at times. At 0900Hrs 31F, PP/graupel mixed, backing to S1. Barometer rising now. Snow surface had become heavy and dense. Touring out to Pussyfoot, we saw the west facing slope above the Hut around 8700’?? had a new slide with a 2-3 foot crown, possible 200 yards in length running up and over a ridge. Cloudy, foggy no photo taken. The same area where a “few more turns” happened? Wind loading and storm slabs present in areas.

Full Snow Observation Report
Centennial Range
Centennieals
Incident details include images

This was shared with me from one of our Fremont County Search & Rescue members. I have no further information.

Full Snow Observation Report
Centennial Range
Centennials - Idaho
Avalanche in the Centennials
Incident details include images

I saw this with my binoculars from several miles away. This is just west of Mt Jefferson and on a southeast facing slope.

Full Snow Observation Report
Centennial Range
Centennials - Montana
Hellroaring Canyon

Yesterday, I skied into Hellroaring Canyon with a group of 6 backcountry skiers staying the night at Hellroaring Hut. While guiding the skiers to the hut, we saw large deposits of avalanche debris in the bottom of major slide paths on west and southwest facing aspects of Mt. Nemesis. It appeared that some of these avalanches were roughly size 1 - 2.5. Numerous creek bottoms and cut banks had also avalanched into Hellroaring Creek. Even some very low angle NW facing gully features had been ripped out. Looking across the valley into the Blair Lake area, I noted only one very small slide on a steep, rocky aspect. I did not have a chance to dig a snow pit, but I did observe numerous huge “whoompfs” while ski touring, and it was obvious that the faceted layer underneath last week’s 6 inches of new snow was failing regularly.

Full Snow Observation Report
Centennial Range
Centennials - Idaho
Centennial Mountains between Reas and Taylor peaks
Incident details include images

We rode this area all day. No one in the group had ever ridden this area, so it was an exploitation day. I dug a pit on a S facing 10* slope at 8564’.
HS 144 with 6 distinct layers, everything above 60cm was fairly consistent, the bottom 60 was JUNK, all large grain facets that were very soft, with little to no cohesion. I was surprised by the failure I got at 132cm, it failed very easily on the shovel shear, and with a CT11. I got an ECTN17 also at 132cm, nothing else. I did a PST just for the sake of killing time at had a 15/end at the 60cm interface. If there is a large enough trigger I have no doubt that the current slab is capable of propagating, and if it does the slide will likely be big. We did not see any avalanche activity while riding or driving in.

Full Snow Observation Report
Centennial Range
Centennials - Montana
Hell Roaring Creek
Incident details include images

Remote triggered several slides from bottom of slope on south facing slope.

Full Snow Observation Report
Centennial Range
Centennials - Montana
Hellroaring Drainage
Incident details include images

Shallow snowpack ~30", west facing terrain around 8200' is faceted except for the top 6 inches. We observed poor structure and fair to good strength due to a lack of distinct layering (its mostly facets top to bottom).

On an east facing slope at 8,300' we observed a slightly deeper snowpack, but still widespread faceting. Poor structure but good strength. During a pit test at this aspect we did not get propogation on any layers (on 1/5/19.) This was all before the most recent round of snowfall however, clearly the facets present a major persistent layer that will cause issues with increased loading.

Full Snow Observation Report

Avalanche Activity- Centennial Range & Lionhead

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

Photos- Centennial Range & Lionhead

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

  • From e-mail: "Widespred slide activity from the last storm cycle, e.g. 2/14-2/18 ranging from E-NE to W. Aspects all elevations, creek bottoms slid at 7000' and peaks slide at 9800'. DEEP crownlines. From a dist. 4'-6', mostly in wind loaded terrain, micro-ridges, and corniced areas." Photo: S. Hansen

  • From e-mail: "Widespred slide activity from the last storm cycle, e.g. 2/14-2/18 ranging from E-NE to W. Aspects all elevations, creek bottoms slid at 7000' and peaks slide at 9800'. DEEP crownlines. From a dist. 4'-6', mostly in wind loaded terrain, micro-ridges, and corniced areas." Photo: S. Hansen

  • 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

  • This was one of multiple avalanches triggered remotely from low-angle slopes connected to steep terrain in the Gravelly Range on Sunday. Photo: S. Olson

  • 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

  • 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).

  • 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 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

  • Avalanche triggered remotely by a snowmobiler near Lionhead Ridge on January 7, 2019. From email "24 inch crown and about 200 feet wide... on an easterly wind loaded slope"

  • A snowpit on Lionhead revealed two weak layers. One was under wind blown snow; the other was 1.5 feet above the ground on a thick layer of sugary facets. Photo: GNFAC

  • From e-mail: "This was a snowmobile triggered slide in a S aspect in the Blue Creek Drainage SE of Reas Peak in the Centennials.  No one was caught and no injuries as far as I can tell".

  • This avalanche in Airplane Bowl off Lionhead Ridge, is south facing at 9,000'. The avalanche was 1-2' deep, 100' vertical and 150' wide (estimated). It likely broke late Sunday or Monday (12/31), during or immediately after the Avalanche Warning. Weak, faceted snow could not support the weekends snowstorm and there were widespread slides. Photo: GNFAC

  • Collapsing and cracking in Watkins Creek in Lionhead. The snow is weak and collapses like this indicate instability. Photo: B. Rasmussen

  • Collapsing and cracking in Watkins Creek in Lionhead. The snow is weak and collapses like this indicate instability. Photo: B. Rasmussen

  • The snowpack at 9,000' above Hebgen Lake near West Yellowstone is 60-70cm (~2 feet) deep. It is mostly weak, sugary facets and will struggle to support the weight of future storms. Photo: GNFAC

  • From email: "7,500' West facing in the Hellroaring Drainage 12/22/18"

    Photo: S. Hansen

  • A skier reported a recent slab avalanche at Ernest Miller in the southern Madison. This is a good reminder that as you move further south in our advisory area, we are seeing a thinner and generally less stable snowpack. Photo: C. Grote

  • The Lionhead area near West Yellowstone has the shallowest and weakest snowpack in our forecast region. The bottom half of the pack consists of weak, sugary facets. This well developed weak layer produced unstable results in stability tests on any slope that had wind drifted snow. With more snow and wind in the forecast, this area will experience increasingly unstable conditions. Photo GNFAC  

Weather Forecast- Centennial Range

Extended Forecast for

10 Miles ESE Lakeview MT

  • Today

    Today: Sunny, with a high near 36. North wind around 10 mph.

    Sunny

    High: 36 °F

  • Tonight

    Tonight: Clear, with a low around 15. North wind 9 to 11 mph.

    Clear

    Low: 15 °F

  • Tuesday

    Tuesday: Sunny, with a high near 37. North northeast wind around 10 mph.

    Sunny

    High: 37 °F

  • Tuesday
    Night

    Tuesday Night: Clear, with a low around 18. Northeast wind around 10 mph.

    Clear

    Low: 18 °F

  • Wednesday

    Wednesday: Sunny, with a high near 42. Northeast wind 9 to 14 mph becoming southeast in the afternoon.

    Sunny

    High: 42 °F

  • Wednesday
    Night

    Wednesday Night: Mostly clear, with a low around 23.

    Mostly Clear

    Low: 23 °F

  • Thursday

    Thursday: Mostly sunny, with a high near 44.

    Mostly Sunny

    High: 44 °F

  • Thursday
    Night

    Thursday Night: Mostly cloudy, with a low around 26.

    Mostly Cloudy

    Low: 26 °F

  • Friday

    Friday: A slight chance of snow after noon.  Mostly cloudy, with a high near 39.

    Mostly Cloudy
    then Slight
    Chance Snow

    High: 39 °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.


  <<  This is the most recent forecast.