24-25

Date

Thu, 01/16/2025 - 14:00

Activity

Snowmobiling

We rode under the full length of Skyline ridge under all the south facing slide paths.

The only avalanches we spotted were from 1-2 weeks ago. No cracking or collapsing observed.

Snowpack

Depths ranged from about 1m to 1.5 m. The snow really got shallow as we rode west and down the cabin creek drainage. Above 8800ft and closer to the Teepee/Cabin divide, coverage was great.
The layer of facets from early December is much weaker where the snow is less than 1 m deep and gaining strength where the snow is around 1.5m deep.
Conditions didn't seem dangerous. Remotely triggering a slide seems very unlikely. The odds of triggering a slide on those facets seems pretty low but still something that could happen.
What mainly felt dangerous is letting your guard down. With tracks everywhere, sunshine, great traction, and supportable snow, we felt that it would be easy to be complacent. If an avalanche happened, then we'd be unprepared.
The odds of triggering a persistent slab avalanche will continue to step down unless there is another loading event (ie - more wind and snow).

Moving foward

The danger and avalanche conditions will be dependent on weather. A small amount of snow and very cold weather is expected in the next 5 or so days
Wind could still form more wind slabs
The inch or two or three of snow that could come Fri/Sat will be subjected to bitter cold weather and could create a new faceted layer...time will tell
Continue to maintain safe travel practices: exposing only one person at a time to avalanche terrain, having everyone else watch from a safe location, ensuring everyone has rescue gear and knows how to use it.

Overall impression - The snowpack in this area probably isn't as stable or strong as it is in the Northern Madison Range closer to Big Sky. The snowpack is probably stronger and more stable than on Lionhead.

Region

Southern Madison

Location (from list)

Cabin Creek

Observer Name

Staples & Hoyer

Spanish peaks wind transport

Date

Thu, 01/16/2025 - 15:00

Large wind transport in Spanish peaks

Region

Northern Madison

Observer Name

Trent Blakeway

Hoarfrost and Suncrust

Date

Thu, 01/16/2025 - 13:00

Activity

Skiing

19°, with hoarfrost on the Erma Road this morning. Suncrust from yesterday (?) on SE aspects in open meadows ranging from 9400' to 8400'.

Region

Cooke City

Location (from list)

Republic Mountain

Observer Name

Traute Lynn Parrie

Windy in Hyalite

Date

Thu, 01/16/2025 - 09:50

Activity

Skiing

Lots of snow moving around in Hyalite this morning! Strong winds were moving snow at/above treeline, Lee aspects getting loaded. Observed a fresh slide on the north side of Mt Blackmore, crown was already filling in, but looked to be a foot or two deep in steep rocky terrain to the skiers left of the north couloir. Some big snow bombs coming out of the trees on the trail right onto your head.

Region

Northern Gallatin

Location (from list)

Mt Blackmore

Observer Name

Spencer Jonas

Cornice Failure

Date

Wed, 01/15/2025 - 12:40

Activity

Skiing

Saw cracking of cornices on the ridgeline NE of Mount Blackmore. Just a little nudge released a significant portion. A good reminder to give cornices room above and below.

Other than that, it was a beautiful day of skiing with sun, moderate temps, and pow. 👍

Region

Northern Gallatin

Observer Name

Shep

GNFAC Avalanche Forecast for Thu Jan 16, 2025

Snowpack and Avalanche Discussion

Persistent slab avalanches remain possible on a layer of facets 1-3 feet deep. This layer is the weakest near <a href="https://www.mtavalanche.com/node/33529"><…; as well as many lower elevation areas where people ski like <a href="https://www.mtavalanche.com/node/33579"><… Creek</a> and <a href="https://www.mtavalanche.com/node/33534"><… Rind</a>. A large, naturally triggered avalanche was spotted from the air <a href="https://www.mtavalanche.com/node/33582"><… Red Mountain</a> in the southern Madison Range yesterday just west of Ernest Miller Ridge.

Even though the likelihood of triggering one of these persistent slab avalanches is dropping, this isn’t a problem to mess with. UAC Moab forecaster, <a href="https://utahavalanchecenter.org/blog/71743"><sp… Trenbeath wrote a great post</a> about this exact situation years ago when he was caught in one of these avalanches when the danger was “only moderate.”

The snowpack is deeper and appears stronger in most snowpits near Cooke City and Island Park. I’m not totally sure why, but Cooke City (scroll through all the <a href="https://www.mtavalanche.com/snow-observations-list?field_regions_simila… observations</a>)  has also had more avalanche activity than most other areas with some large ones breaking up to 4-6 ft deep. Cooke does have much more high alpine terrain which could be a factor. Near Island Park the snowpack is pretty deep with similar layering, but there has been very little reported avalanche activity.

Old wind slab avalanches can also be triggered near ridgelines. Look for signs of previous wind drifting to avoid these places.

The key today is terrain selection. Slopes less than 30 degrees in steepness that aren’t steep enough to slide are always the safest option. If getting onto steeper terrain, remember that bigger avalanches happen in bigger terrain, so consider smaller terrain with a clean runout to reduce the consequences of a slide if one happens. Today the avalanche danger is MODERATE.

Wind has been the dominant weather factor in the mountains near Bozeman and Big Sky making old wind slab avalanches the main concern. Winds have done their work and don’t have much snow left to transport.

Persistent slab avalanches have become mostly unlikely in many areas where the snowpack has gotten deeper, but they are a lingering concern in places with shallower snow. I found both of these situations while <a href="https://www.mtavalanche.com/node/33572"><… yesterday in Beehive and Middle Basins</a>. Ian and Dave found a similar story in <a href="https://www.mtavalanche.com/node/33557"><… Creek</a> and I found the same thing on <a href="https://www.mtavalanche.com/node/33443"><… Blackmore</a>.

Heads up - At lower elevations, especially near exposed rocks that add extra heat to the snow, wet loose avalanches will be a concern today. Ice climbers are particularly vulnerable and should watch for heating of the snow. One observer found many <a href="https://www.mtavalanche.com/node/33569"><… slides covering the trail </a>along the Unnamed Wall in Hyalite yesterday.

Today, the avalanche danger is MODERATE with heightened avalanche conditions in areas with previous wind loading, areas with thin snow, and lower elevation areas where the snow becomes wet.