22-23 | Gallatin National Forest Avalanche Center

Skier triggered slide in Lone Mountain backcountry

Date

Thu, 02/02/2023 - 16:40

Big Sky Ski Patrol reported a skier triggered avalanche in "The Mullet" in the backcountry outside the ski resort boundaries. One skiers was reportedly caught and carried by the slide. The initial skier triggered slide also triggered another avalanche in the adjacent "Rattail" avalanche path. Details are second hand and specifics could not be confirmed due to low visibility.

Region

Northern Madison

Location (from list)

Lone Mountain

Observer Name

Big Sky Ski Patrol

Whumpfs in Specimen Creek

Specimen Creek

Southern Gallatin

2/2/2023

Code

Latitude

45.02650

Longitude

-111.04800

Notes

Skiers reported getting several whumpfs in a thin snowpack in Specimen Creek.

Number of slides

Number caught

Number buried

Read more about Whumpfs in Specimen Creek

Snow Observation Source

Poor test scores and whumpfs in Specimen

Slab Thickness units

centimeters

Single / Multiple / Red Flag

Red Flag

Advisory Year

22-23

Poor test scores and whumpfs in Specimen

Date

Thu, 02/02/2023 - 16:45

Activity

Skiing

Just wanted to report that I found very thin snow on west aspects in Specimen Creek, with unstable test results today.

Had an ECTP 13 down about 20 cm on the new/old snow layer from last weekend. Couple whoomphs, and observed some stiff WS formation on ridge lines. HS of 90cm and absolute junk on the bottom.

Great skiing on non-avalanche terrain, however.

Region

Southern Gallatin

Location (from list)

Specimen Creek

Observer Name

Matt Standal

The Throne - Fewer Signs of Instability

Date

Thu, 02/02/2023 - 14:05

Activity

Skiing

Snowmobiling

We skinned up the ridge of the Throne, and we dug two quick pits on the lower half of the slope. On the E aspect at 7,800' we had a HS of 4 feet. We got an ECTP 24 and 30 on the facets at the ground. 30 feet away, we dug a pit with less than 3 feet of snow, and we got an ECTX in that pit. This showed how spatially variable this area is after the new snow and wind. We continued skinning up the ridge to the top of the Throne, and we dug another pit. Here, we found 190 cm of snow, and we had an ECTP 14, 1.5' below the surface within the new snow from the last week. We did not see other signs of instability while touring or riding today.

Region

Bridger Range

Location (from list)

The Throne

Observer Name

Ian Hoyer, Alex Haddad

Don't step out too quickly, Bridger Range - 2 Feb 2023

Read more about Don't step out too quickly, Bridger Range - 2 Feb 2023

Poor structure in YNP

Date

Wed, 02/01/2023 - 11:00

Activity

Skiing

Skied near Bacon Rind Creek on 2/1/2023. Surprisingly little wind affect, still some snow on trees and a soft snow surface. Excellent low angle powder skiing in wind protected areas. Underlying snow structure very weak though. Weak layer likely from the December cold snap buried ~40-50cm from surface is super concerning, not to mention basal weak layers and new snow interface... New snow from the 1/27-1/28 storm has settled to a soft slab (F-4F) 35cm thick. Still lots of snow available for transport.

Region

Southern Madison

Location (from list)

Bacon Rind

Observer Name

Matt Zia

Mt Ellis (main summit)

Date

Wed, 02/01/2023 - 03:40

Activity

Skiing

100 cms of snow in the meadow at the head of Moonshine. So much snow took a long time to make it to the top. I have not seen the summit area wind affected like it is for a long time. Actually dug a pit and performed an ECT approximately 50 meters north of the of the burn on an east facing swallow angle slope. Pit depth 135 cms. There was a thin hard/ice layer at mid depth in the snow. ECTN with initiations at 2 locations in the upper half of the snow pack. An encouraging sign is the strengthening of the facted snow at the ground. Skiing in the trees was good, the snow is dense.

Region

Northern Gallatin

Location (from list)

Mt Ellis

Observer Name

David Combs

GNFAC Avalanche Forecast for Thu Feb 2, 2023

Snowpack and Avalanche Discussion

In the mountains of southwest Montana two competing forces are at play. On one hand, after getting a good wallop of snowfall Friday and Saturday, buried weak layers that did not avalanche will become less reactive. On the other hand, the wind continues to blow and load slopes at all elevations and aspects which hinder this process. Additionally, we are untrusting souls at the moment. Weak layers of buried facets continued to break in every snowpit Dave and his partner dug in Cooke City (<a href="https://www.mtavalanche.com/node/27934"><span… details and videos</a>), and on Tuesday I was able to trigger a small avalanche in Lionhead from 50 feet away, a crystal clear sign of dangerous conditions (<a href="https://youtu.be/hpLK-1vISH0">…;). Further evidence of our snowpack’s instability include Saddle Peak avalanching twice in a week and all the avalanche activity that blanketed our area as recently as Tuesday (<a href="https://www.mtavalanche.com/weather/wx-avalanche-log"><span… and weather log</a>).

Avalanche conditions remain dangerous today. Wind is blowing snow and loading slopes. Weak layers in the top 3 feet of the snowpack, as well as sugary, weak snow at the ground, are still adjusting to the weight of the weekend snow and recent wind-drifting. I recommend you do as Ian I did on Tuesday: we consciously avoided avalanche terrain and runout zones (slopes underneath). Be patient. Stability will improve and slopes will become relatively safer as high pressure settles over us, but we are not there yet. A wise avalanche professional wrote last night, “Decision-making is currently difficult. There are multiple hazards to consider, conditions are dynamic, and obvious.”

For today, the avalanche danger is rated CONSIDERABLE, <a href="https://avalanche.org/avalanche-encyclopedia/human/resources/north-amer… means</a> careful snowpack evaluation, cautious route-finding, and conservative decision making are essential.

Watch our <a href="https://www.youtube.com/playlist?list=PLXu5151nmAvTi1DBS5B4DBCruL1ULhkt… videos</a> and read the <a href="https://www.mtavalanche.com/snow-observations-list"><… page</a> for detailed information about additional field locations. Browse the <a href="https://www.mtavalanche.com/avalanche-activity"><stro… Activity Log</a> and note nearly thirty entries since January 25, many of which include multiple avalanches.

Please share avalanche, snowpack or weather observations via our<a href="https://www.mtavalanche.com/node/add/snow_obs">…; website</a>, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).

Avalanche conditions remain dangerous today. Wind is blowing snow and loading slopes. Weak layers in the top 3 feet of the snowpack, as well as sugary, weak snow at the ground, are still adjusting to the weight of the weekend snow and recent wind-drifting. Avoid avalanche terrain and runout zones (slopes underneath).