22-23 | Gallatin National Forest Avalanche Center

Natural Avlanche N Face of Sunset/Wolverine

Wolverine Peak

Cooke City

1/14/2023

Code

SS-N-R1-D1.5

Aspect

Latitude

45.04690

Longitude

-110.00100

Notes

We observed a north-facing natural sluff turn into a reasonable slide release over the cliff bands from the ridge line between Miller and Wolverine today while skinning on the flat bench above the road out to Wolverine Peak today. I think it released right at Sunset peak. It may have started with a cornice release but was more like wind loading on the steep face. We also saw some minor cracking on north facing wind loaded roll overs above the bench. We opted to descend low-angle trees back to our sled and to go ski Henderson.

Number of slides

Number caught

Number buried

Avalanche Type

Soft slab avalanche

Trigger

Natural trigger

R size

D size

1.5

Problem Type

New Snow

Read more about Natural Avlanche N Face of Sunset/Wolverine

Snow Observation Source

Natural Sluff / Avalanche N Face of Sunset/Wolverine

Slab Thickness units

centimeters

Single / Multiple / Red Flag

Single Avalanche

Advisory Year

22-23

Weather and Avalanche Log for Sun Jan 15, 2023

Read more about Weather and Avalanche Log for Sun Jan 15, 2023

Natural Sluff / Avalanche N Face of Sunset/Wolverine

Date

Sat, 01/14/2023 - 13:45

Activity

Skiing

Snowmobiling

Region

Cooke City

Location (from list)

Wolverine Peak

Observer Name

Cascade Tuholske

Read more about Mt. Blackmore Ridgeline Profile - 14 Jan 2023

Northern Gallatin, 2023-01-14

Access other image sizes:

Read more about Mt. Blackmore Lower Profile - 14 Jan 2023

Northern Gallatin, 2023-01-14

Access other image sizes:

Read more about Blackmore Meadows Profile - 14 Jan 2023

Northern Gallatin, 2023-01-14

Access other image sizes:

Mt. Blackmore Varying ECT Scores

Date

Sat, 01/14/2023 - 14:45

Activity

Skiing

We toured up to the Mt. Blackmore ridgeline today. Near Mt. Blackmore most of the snow was wind affected, and today’s winds at the ridgetops were not blowing snow around because there is little snow left for the wind to transport. We dug three pits on different aspects and elevation bands, and we didn’t find surface hoar in any of these pits.The pits we dug had facets near the surface all the way to the bottom of the snowpack, and it was capped with a 1-3” of wind-packed snow. We were able to get an ECTP18 on facets above a crust 10” below the surface on a SE aspect at 9,500’. And, we got an ECTP18 on a NE aspect at 9,800’ in a shallow, wind stripped area below Mt. Blackmore’s ridgeline. This was in a layer of facets 2 feet below the surface. We were not able to replicate these results in either snowpit. Buried weak layers are getting harder to trigger, and these pits showed how finding a thin spot on a slope could still trigger an avalanche.

Region

Northern Gallatin

Location (from list)

Mt Blackmore

Observer Name

Alex Marienthal, Alex Haddad

Decreasing Likelihood and Danger - 14 Jan 2023

Read more about Decreasing Likelihood and Danger - 14 Jan 2023

GNFAC Avalanche Forecast for Sat Jan 14, 2023

Snowpack and Avalanche Discussion

Strong south and west winds are creating fresh drifts out of the snow that fell this last week. Avalanches could break in the newly drifted snow or on weak layers deeper in the snowpack. Skiers this week triggered a couple of thin wind slabs (<a href="https://www.mtavalanche.com/node/27633"><span…; <a href="https://www.mtavalanche.com/node/27648"><span…;). With increased winds overnight they will be more widespread today. Look out for pillows of drifted snow and steer around them to avoid triggering a slide. Cracks shooting out in front of your skis or sled are clear signs that you’ve found unstable drifts. These drifts will be most dangerous where they’re deepest and where they’re sitting over persistent weak layers.

The most worrisome weak layer is a surface hoar layer buried about a foot deep (tending to be deeper in southern areas and slightly shallower to the north). We’ve found it all over the advisory area, even on wind affected slopes where surface hoar usually gets destroyed before being buried (<a href="https://www.youtube.com/watch?v=hk_6xgHgTCo">… ridge</a>, <a href="https://youtu.be/1mFc__nNwIk">…;, <a href="https://youtu.be/ECi646U0Rtg">… Fork</a>, <a href="https://youtu.be/iBS_5itbX_U">… City</a>). Last night’s wind may have transported enough snow to tip the scale on this layer and cause avalanches. Dig down to test this layer before riding steep slopes.

There is also still weak snow in the middle of the snowpack and near the ground. You’re most likely to trigger an avalanche on these facets from a thin spot. Identify and avoid likely thin areas and be on high alert if you’re suddenly punching through to the ground (<a href="https://www.mtavalanche.com/images/23/sinking-waist-deep-faceted-snow">… waist deep into facets photo</a>). Stability tests are not going to be very helpful in identifying slopes where these layers are unstable, so simply toning down your terrain choices is the best solution. Make sure you have a partner watching from a safe spot if you’re riding steep slopes. Large avalanches remain possible and the danger is rated MODERATE across the advisory area.

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).

In Island Park, strong south and southwest winds are creating fresh drifts out of the snow that fell this last week and new snow today. Avalanches could break in the newly drifted snow or on weak layers deeper in the snowpack. The most worrisome weak layer is a surface hoar layer buried about a foot deep. Dig down to test this layer before riding steep slopes. Tone down your terrain choices in case you trigger a deeper slide. If heavy snowfall materializes today, instability will rise rapidly.