22-23

Taylor Fork

Southern Madison

1/28/2023

Code

HS-N-R2-D2-O

Aspect

Latitude

45.06590

Longitude

-111.28200

Notes

We rode to the Taylor Fork weather station (near Pika Point on the rim of Sunlight Basin) and noticed a few slides along the way. At the weather station we could see that the north end of the basin natural avalanched: the slopes from where the cornices end in Sunlight Basin past Pika Point. It broke up to 2.5 feet deep on an old layer of facets and surface hoar. The slide was R2 D2, 3-400 feet vertical and at least 750 feet wide. It was a large Hard Slab. We spent time at the crown digging, making a movie and getting cold. No surprises, just great to see a real avalanche. We also saw smaller slides looking west from the station, close by. Afterward, we rode to the Sage/Carrot divide in deep snow; hero riding. Skyline Ridge was obscured in clouds.

On the drive back to Bozeman we could see many slides on road cuts and on slopes across the river; low elevation avalanches that we don’t get to see often.

The avalanche recorded in this form is the one in Sunlight Basin that we made the movie about.

Number caught

Number buried

Avalanche Type

Hard slab avalanche

Trigger

Natural trigger

R size

D size

Bed Surface

O - Old snow

Problem Type

Persistent Weak Layer

Read more about Many natural slides in Taylor Fork

Slab Thickness

30.0 inches

Vertical Fall

400ft

Slab Width

750.00ft

Weak Layer Grain type

Surface Hoar

Weak Layer grain size

3.10mm

Weak Layer Hardness

Slab Layer Grain Type

Wind packed

Slab Layer Grain Size

1.00mm

Slab Layer Hardness

1F+

Attached Videos

Natural Avalanche, Taylor Fork - 28 Jan 2023

Snow Observation Source

Many natural slides in Taylor Fork

Slab Thickness units

inches

Single / Multiple / Red Flag

Multiple Avalanches

Advisory Year

22-23

Rider triggered slide on Buck road cut

Buck Ridge

Northern Madison

1/27/2023

Code

SS-AM-R2-D1-I

Elevation

8000

Aspect

Latitude

45.17190

Longitude

-111.38000

Notes

We rode through 1st, 2nd, and 3rd Yellowmule. Measured 13” of new snow with 0.6” SWE in 1st Yellowmule at 10 am. This brought the two day snow total to approximately 20”. Snowed all day with varying intensity and there were strong west winds along the ridge.

Visibility wasn’t great, but we saw most of the avalanche terrain in the Yellowmules. ..... saw a very small snowmobile triggered avalanche on a roadcut on the way out (6-12 inches deep, ~20 ft wide) that broke on facets in the thin snowpack.

Number of slides

Number caught

Number buried

Avalanche Type

Soft slab avalanche

Trigger

Snowmobile

R size

D size

Bed Surface

I - Interface between new and old snow

Problem Type

New Snow

Read more about Rider triggered slide on Buck road cut

Slab Thickness

12.0 inches

Vertical Fall

50ft

Slab Width

50.00ft

Weak Layer Grain type

Faceted Crystals

Slab Layer Grain Type

Precipitation Particles

Images

Rider triggered avalanche on road cut, Buck Ridge

Attached Videos

New snow, dangerous conditions - 27 Jan 2023

Snow Observation Source

Deep storm day on Buck

Slab Thickness units

inches

Single / Multiple / Red Flag

Single Avalanche

Advisory Year

22-23

GNFAC Avalanche Forecast for Sat Jan 28, 2023

Snowpack and Avalanche Discussion

<a href="https://www.mtavalanche.com/weather/wx-avalanche-log"><span… totals are impressive</a>:

<ul>
<li>29” (3.5” snow water equivalent, SWE) in the Bridger Range</li>
<li>18” (1.7” SWE) in Hyalite</li>
<li>24” (1.7” SWE) in Big Sky</li>
</ul>

It is very dangerous in the backcountry. Heaps of snow are creating avalanches, both natural and human triggered. Today is a day to stay out of avalanche terrain, including runout zones. Avalanches can be triggered from afar (remotely) and can propagate uphill. Weak snow near the ground and/or other weak layers will break and avalanche with this new load. This is not a day to dig snowpits to try and outsmart the avalanche. Avoidance is the only tactic that works. Ian and Alex rode into Buck Ridge yesterday and confirmed the Avalanche Warning (<a href="https://youtu.be/_AKiCAbhppk">…;). There was also a skier triggered avalanche in Lick Creek that was 2-4’ deep (<a href="https://youtube.com/shorts/RBkECAuBzKg?feature=share"><span…;) and a 2.5’ deep slide was remotely triggered in Fairy Lake (<a href="https://www.mtavalanche.com/node/27849"><span…;). Triggering avalanches is very likely today. During and immediately after storms is when avalanches are ripe to occur. As weather and visibility improves, do not err and assume the danger has passed, because it has not. Today the snowpack needs time to adjust to its new load. It can’t be rushed and the avalanche danger is rated HIGH.

Near West Yellowstone and Cooke City the mountains have dangerous avalanche conditions. In Cooke City yesterday, Beartooth Powder Guides reported 2-3 feet of new snow at higher elevations, far more than the automated weather stations are recording. Even with limited visibility, avalanches in the new snow were seen around Cooke City (observation <a href="https://www.mtavalanche.com/node/27848"><span…; <a href="https://www.mtavalanche.com/node/27843"><span…; <a href="https://www.mtavalanche.com/node/27840"><span…;). The southern Madison Range, southern Gallatin Range and Lionhead area have gotten at least a foot of snow in the last 2 days. A buried weak layer (feathery surface hoar crystals) was avalanching before the storm, which means today it will be easy to trigger avalanches. While the southern mountains are not quite at Avalanche Warning criteria, they still warrant serious respect. Give all avalanche terrain a wide berth today and don’t poke the bear.

For today, the avalanche danger is rated CONSIDERABLE on all slopes since triggering avalanches is likely.

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).

The mountains have dangerous avalanche conditions. A buried weak layer (feathery surface hoar crystals) was avalanching before the storm, which means today it will be easy to trigger avalanches. While the southern mountains are not quite at Avalanche Warning criteria, they still warrant serious respect. Give all avalanche terrain a wide berth today and don’t poke the bear.

Read more about GNFAC Avalanche Forecast for Sat Jan 28, 2023

KING AND QUEEN OF THE RIDGE, FEBRUARY 4TH

Weather and Avalanche Log for Sat Jan 28, 2023

Read more about Weather and Avalanche Log for Sat Jan 28, 2023

AVALANCHE WARNING continues for N. Gallatin, N. Madison, and Bridger Ranges

Remotely triggered avalanche in Fairy Lake

Fairy Lake

Bridger Range

1/27/2023

Code

ASr

Latitude

45.90430

Longitude

-110.95800

Notes

From IG:

Fairy lake today, from top of the ridge

About 2-2.5ft deep about 75-100 ft wide

Number of slides

Number caught

Number buried

Trigger

Skier

Trigger Modifier

r-A remote avalanche released by the indicated trigger

Read more about Remotely triggered avalanche in Fairy Lake

Slab Thickness

30.0 inches

Slab Width

90.00ft

Snow Observation Source

Remotely triggered avalanche in Fairy Lake

Slab Thickness units

inches

Single / Multiple / Red Flag

Single Avalanche

Advisory Year

22-23

Many naturals, Cooke City

COOKE CITY

Cooke City

1/27/2023

Code

Latitude

45.02020

Longitude

-109.93800

Notes

2-3 feet of new snow was reported above Round Lake in Cooke City. Many natural avalanches were seen on S-SE slopes. From afar they look to be breaking on new-old snow interface.

Number caught

Number buried