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Read more about The Throne Lower East Face Profile - 19 December 2024

Bridger Range, 2024-12-19

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Pleasantly Surprised on The Throne

Date

Thu, 12/19/2024 - 13:00

Activity

Skiing

Today, we rode up to The Throne for the first time this season. We parked at the motorized boundary and toured up the east face. The road riding was good but there were certainly more dirt patches on the way out, than in, with the warm temps.

We dug two pits on the east face as we ascended. At 7950' we had HS: 78, ECTN13 + 23. At 8140', we got HS: 97, ECTN 30. We toured up the ridge and moved over onto a north aspect. There we got HS: 94, ECTN 30. We observed no cracking or collapsing. Weak layers still exist at the bottom of our snowpack, but we were happy to find that these weak layers in the Bridgers seem to be not quite as weak as in our other zones.

We had good visibility and were able to get eyes on two avalanches that occurred naturally during the major wind event yesterday in the bowl south of Naya Nuki. The largest of which was a R2-D1.5 that broke in the new snow. We also got eyes on a natural avalanche (R2-D2.5) that occurred yesterday on Saddle Peak.

Region

Bridger Range

Location (from list)

The Throne

Observer Name

H. Darby

Flanders Obs & Test Scores

Date

Thu, 12/19/2024 - 12:00

Activity

Skiing

Toured up Flanders Peak this morning—a beautiful day with clear skies and no/light winds.

During our ascent, we observed widespread wind effects above 8800'. The west-facing ridge of the drainage was scoured of snow, while wind loading was observed on E/SE aspects between 8800' and the summit. 1-5" thick wind slabs were widespread, and were especially of note at lower elevations in the east-facing trees; increasing depth and stiffness as we ascended and on Flanders' E shoulder. Got a few small whumpfs along the E shoulder while ascending, but no other signs of instability on the day. Several small test slopes we traversed along the ridge did not show signs of instability when we tested them.

The power of the winds was emphasized by the scoured west side of the East Ridge of the Main Fork.

We skied the slope in the trees south of the summit and dug a pit on a SE aspect @ 9530'. Skiing quality was low. Snowpit depth was 72cm. Test results were CT11 SP, ECTN8, PST 44/100 (End).

Region

Northern Gallatin

Location (from list)

Flanders Creek

Observer Name

E. Webb

natural avalanche activity, Cooke City

Date

Thu, 12/19/2024 - 11:40

Activity

Snowboarding

Quite a few natural avalanches observed north of Cooke City today. Photos attached of:

1: NE facing, 10,000, Miller Ridge

2: E facing, 9900', Bull of the Woods Pass

3: NE facing, 9700', Miller Ridge

4: E facing, 10,200' Scotch Bonnet Mtn.

5: E facing, 10,000 Mt. Henderson

6-8: NE- N facing, 10,000' Mt. Henderson

9: NE facing, 10,000' Sheep Creek.

There was also a large avalanche event on the E aspect of Fisher Mtn, which I didn't photograph. But there were some other skiers nearby who likely had a good view of it.

Also, we had 4 large collapses today. One on a southerly aspect, and the other 3 on NE aspects. All around 9800'.

Region

Cooke City

Location (from list)

COOKE CITY

Observer Name

B. Fredlund

Natural Avalanche on Arden Pk.

Date

Thu, 12/19/2024 - 10:40

Activity

Skiing

Observed from Flanders this morning. Presumed recent natural slide around ~9950 ft. on a E/NE aspect. Hard to tell from a distance, but cornice interference and/or wind loading are possible culprits. Poor image quality, but there may be more debris piles along the ridgeline to the south.

Region

Northern Gallatin

Location (from list)

Maid of the Mist

Observer Name

E. Webb

Natural avalanche, Saddle Peak

Saddle Peak

Bridger Range

12/18/2024

Code

N-R2-D2.5

Elevation

9100

Aspect

Latitude

45.79430

Longitude

-110.93600

Notes

There was a natural avalanche on Saddle Peak on Wednesday, December 18. Strong winds ripped through new snow and loaded many slopes. The avalanche broke an estimated 250 feet wide, 1-3 feet deep, and ran 1500 vertical feet.

Number of slides

Number caught

Number buried

Trigger

Natural trigger

R size

D size

2.5

Problem Type

Wind Slab

Read more about Natural avalanche, Saddle Peak

Slab Thickness

24.0 inches

Vertical Fall

1500ft

Slab Width

250.00ft

Images

Natural on Saddle- zoomed

Natural Avalanche on Saddle Peak

Slab Thickness units

inches

Single / Multiple / Red Flag

Single Avalanche

Advisory Year

24-25

Read more about Natural Avalanche on Saddle Peak

Avalanche Details: Natural avalanche, Saddle Peak

Bridger Range, 2024-12-19

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Weather and Avalanche Log for Thu Dec 19, 2024

Read more about Weather and Avalanche Log for Thu Dec 19, 2024

Snow was falling in Cooke yesterday, but with wind hard to measure how much

Sawtell rimed again

GNFAC Avalanche Forecast for Thu Dec 19, 2024

Snowpack and Avalanche Discussion

A persistent slab avalanche problem exists throughout the forecast area with a weak layer of faceted snow buried 1-2 feet deep on nearly all slopes. This weak layer formed on top of the snowpack during dry weather in the first two weeks of December, and in some places it includes a layer of <a href="https://www.mtavalanche.com/node/32524"><… hoar</a>. A few small storms capped this weak layer, and then snowfall from Saturday night through Tuesday built a slab on top of it. That snow also dramatically improved skiing and riding conditions.

<ul>
<li><a href="https://www.mtavalanche.com/node/32540"><… group</a> in Beehive Basin yesterday found this layer producing unstable results in snowpack tests.</li>
<li>A group in <a href="https://www.mtavalanche.com/node/32523"><…; had a similar observations.</li>
<li>My riding partners and I found this weak layer <a href="https://www.mtavalanche.com/snow-observations-list"><… Sawtelle Peak</a> near Island Park on Tuesday.</li>
<li>A <a href="https://www.mtavalanche.com/node/32522"><… near Cooke City</a> yesterday experienced shooting cracks.</li>
<li>Dave and his partner found it <a href="https://www.mtavalanche.com/node/32482"><… Cooke City</a> on Monday & Tuesday</li>
</ul>

See the full list of observations <a href="https://www.mtavalanche.com/snow-observations-list"><…;

Yesterday’s winds left few slopes untouched - loading many with wind blown snow or creating a more cohesive slabs on other slopes without obvious drifting. Whether a wind slab is present or not, the end result is that persistent slab avalanches remain likely.

The challenge today is that you may not get direct feedback from the snowpack with obvious signs like shooting cracks or <a href="https://avalanche.org/avalanche-encyclopedia/#collapse-or-whumpf"><span…;. Yesterday in <a href="https://www.mtavalanche.com/node/32524"><… Basin near Big Sky</a>, Ian and I couldn’t find any of those obvious clues, but a quick snowpit and an extended column test immediately showed us the problem.

Recent avalanche activity (view all activity <a href="https://www.mtavalanche.com/avalanche-activity"><stro…;) has been a bit on the small side, but I expect avalanches today to be larger as a result of yesterday’s winds creating a more cohesive slab.

The combination of a widespread weak layer, recent snowfall followed by major wind loading, recent avalanche activity, and consistently poor snowpack test results indicates dangerous avalanche conditions. For this reason the avalanche danger is CONSIDERABLE. Seek out slopes less than 30 degrees in steepness relatively sheltered from the wind for the best and safest conditions today.

Read more about GNFAC Avalanche Forecast for Thu Dec 19, 2024

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Unstable test results in Beehive

Date

Wed, 12/18/2024 - 12:00

Activity

Skiing

My friend and I toured in Beehive this morning. Was calm early but the winds picked up late morning and were whipping around pretty good as we left mid-afternoon. Dug a quick pit at ~9300 ft along the upper east side of the west ridge of Beehive Basin (lower end in the timber before it gets exposed in the upper basin). Snowpack was ~120cm deep, approximately half of that being from the last storm series. We got an ECTP11 that was a smooth propagation which failed ~65 cm up from the ground at the interface of the new storm snow. This reinforced the instability we expected to find and we stuck to a few laps of the smaller / gentler east facing meadows. Skiing was great though! With the wind today I’m sure the instability will only get worse before it gets better…

Region

Northern Madison

Location (from list)

Beehive Basin

Observer Name

William Moore

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