Regional Conditions for Bridgers

The Bridger Range got 8-10" of new snow overnight (1/19-1/20) on top of 4-6" of snow from Friday (1/18). Last night's snow was equal to 1-1.5" of snow water equivalent. We got stable and unstable results in stability tests, but this heavy new load alone is enough to indicate large avalanches can break within or below this heavy snow. Photo: GNFAC

This crown was part of a human triggered slide that caught and partially buried a skier near Fairy Lake in the northern Bridgers. The skier triggered the slide from low on the slope and was buried up to his chest. Fortunately, he was uninjured and able to dig himself out. Photo: GNFAC 

Skiers near the south boundary of Bridger Bowl observed this natural slide on Saddle Peak below the Football Field. An intense shot of precipitation yesterday created unstable conditions, mainly on steep wind loaded slopes. This slide only involved the new snow and did not break into deeper layers. Fortunately, nobody was involved with this slide. Photo: N. Corwin 

Conditions are firm and wind hammered in the northern Bridgers. Slide for life conditions are just as much of a hazard as avalanches. Although conditions are generally stable, all steep slopes should be assessed before dropping in. Photo: GNFAC 

Skiers on the west side of the Bridgers found poor structure and signs of instability on Sunday. From the email: "We found a soft 4 finger layer about a foot thick over 6 to 12 inches of large grained facets that wouldn’t let us isolate a column. As we skinned up, we experienced whoomphing and cracking in the snow." Photo: P. Hinz

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).

Skiers found a variable snowpack near Frazier Basin in the northern Bridgers. This south-facing slope had a foot of facets near the ground, which was not present on a nearby northern aspect. Photo: Unknown

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.

Snowpit in the crown of an avalanche that occurred on Saturday (1/5) near Ross Peak. Likely triggered by a snowmobiler as they rode downhill on an adjacent slope. link below for more details. Photo: GNFAC

This avalanche was on a northeast slope of Ross Peak. The observation reported "very firm thick wind slabs with ground level facets" nearby. Photo: J. Johnson

This avalanche was on a northeast slope of Ross Peak. The observation reported "very firm thick wind slabs with ground level facets" nearby. Photo: J. Johnson

Riders observed this slide happen on Saturday (1/5) in the northern Bridger Range, near Battle Ridge/The Throne. 

Riders observed this slide happen on Saturday (1/5) in the northern Bridger Range, near Battle Ridge/The Throne. 

Multiple avalanches released on wind-loaded slopes in the Bridger Range south of Bridger Bowl. The largest propagated a few hundred feet wide on Bridger Peak. Smaller slabs released in the Pinnacles and in Argentina bowl. Photo: A. Schauer

"A 4-14" deep by 30ft wide slab released naturally? below dry martha, we think this morning (1/3/19). it ran approx 300ft over the bottom cliff and stopped near the south bowl traverse." Photo: BBSP

This pit was dug in the same general area as the natural avalanche shown in part (1) of this observation. The pit shows a faceted snowpack capped by the recent storm snow.  Photo: A. Pohl

Skiers in the northern Bridgers noticed this natural slab avalanche that released during the most recent storm cycle.  Photo: A. Pohl

Skiers near Blackmore found the new snow to be failing at the new/old snow interface. They were able to trigger this soft slab of new snow with a ski pole whack. Photo: G. Antonioli

Snow bikers in the northern Gallatin Range found unstable test results on the early December facet layer (12/30). "While snow biking... We dug a snow pit at 9100 ft elevation & discovered a weak layer that propagated at 28 on the ECT test about 18 inches down. The snow below that area was all loosely faceted." Photo: J. Polus

We rode into the 2nd Yellowmule of Buck Ridge and found 2 instabilities: new snow, and facets that formed in early December. The facets are buried 1.5' under the surface and broke with an ECTP24. Two weeks ago we dug in the same spot and got ECTP10. Things are slowly getting stronger, but this weekend's snowstorm may be enough to break it and avalanche. Photo: GNFAC

Skiers observed debris below the Banana Couloir on Ross Peak from an avalanche that failed during the most recent storm cycle. Photo: G. Antonioli

After receiving over a foot of snow in the past few days, skiers in the Bridgers were able to trigger a wind-loaded test slope near the Playground. With more snow in the forecast, storm slabs and wind slabs will remain sensitive over the next few days. Photo: G. Antonioli

Snow that fell in the Bridger Range on Thursday (12/27) was very lightweight and low density. This snow could easily sluff off steep slopes and wind will blow this snow into fresh wind slabs. Photo: GNFAC

Saddle Peak is backcountry terrain located south of Bridger Bowl ski area's boundary. Hazards are not mitigated by patrol and there are no patrol rescue services. You should have the necessary skills and knowledge about snowpack and safe travel before entering this terrain. Photo: GNFAC

On Saddle Peak, strong west wind (Friday) stripped the ridgetop of uncompacted snow that left elevated ski tracks and pole plants behind. Photo: GNFAC

This wind slab released as a result of an intentional ski cut. The initial slab that released was approximately 100 feet wide with a 6-12" crown. It triggered a larger slab that was 300 feet wide and ran close to 2000'. More information in the avalanche activity list. P: M. Cohen

This wind slab released as a result of an intentional ski cut. The initial slab that released was approximately 100 feet wide with a 6-12" crown. It triggered a larger slab that was 300 feet wide and ran close to 2000'. More information in the avalanche activity list. P: M. Cohen

This wind slab released as a result of an intentional ski cut. The initial slab that released was approximately 100 feet wide with a 6-12" crown. It triggered a larger slab that was 300 feet wide and ran close to 2000'. More information in the avalanche activity list. P: M. Cohen

Natural slide on Northern wall of the Hourglass in Northern Bridgers. No tracks in or out. Crown looked to be 8-10” deep and 25-30ft wide. Photo: N. Baird

This wind-loaded slope was triggered Sunday morning (12/16) by a snowmobiler. The debris was hard slabs of wind-drifted snow. The avalanche broke on a layer of small sized facets that formed during the frigid, clear weather 10 days ago. No one was caught. Photo: GNFAC

We found unstable stability test scores (ECTP 11) in this pit. And this drift collapsed with an audible "whumph" and cracks 30 feet wide. A buried layer of surface hoar and facets collapsed under a hard slab that formed from strong winds last night. Photo: GNFAC

Crack in a drift that collapsed 30 feet wide, accompanied by an audible "whumph", as we skinned over it. 12/15/18 West side of Bridger Range. Recent strong winds formed hard slabs over weak surface hoar and facets. Photo: GNFAC

This drift collapsed and cracked 30 feet wide, accompanied by an audible "whumph", as we skinned over it. 12/15/18 West side of Bridger Range. Recent strong winds formed hard slabs over weak surface hoar and facets. Photo: GNFAC

A skier north of Bridger Bowl triggered this small wind slab near the ridge. This is a good reminder that isolated instabilities still exist on wind loaded slopes. Photo: J. Zimmer 

Photo: @msubackcountryclub

A skier in the Northern Bridgers found variable conditions on Saturday, with wind scouring above treeline, isolated wind slabs below treeline, and widespread faceting with the recent cold and dry weather. "Skiing was highly variable, ranging from all loose facets to breakable wind slab overlying facets to hard slab/sastrugi." Photo: G. Antonioli

Wind loads were easy to trigger. This one was triggered on purpose up Maid of the Mist in Hyalite. Photo: A. Peterson