22-23

Many natural slides in Taylor Fork

Taylor Fork
Southern Madison
Code
HS-N-R2-D2-O
Aspect
NE
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
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Natural trigger
R size
2
D size
2
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
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
F
Slab Layer Grain Type
Wind packed
Slab Layer Grain Size
1.00mm
Slab Layer Hardness
1F+
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Rider triggered slide on Buck road cut

Buck Ridge
Northern Madison
Code
SS-AM-R2-D1-I
Elevation
8000
Aspect
E
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
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Snowmobile
R size
2
D size
1
Bed Surface
I - Interface between new and old snow
Problem Type
New Snow
Slab Thickness
12.0 inches
Vertical Fall
50ft
Slab Width
50.00ft
Weak Layer Grain type
Faceted Crystals
Slab Layer Grain Type
Precipitation Particles
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

GNFAC Avalanche Forecast for Sat Jan 28, 2023

Snowpack and Avalanche Discussion

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

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

<p><span><span><span><span><span><span>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 (</span></span></span></span></span></span><a href="https://youtu.be/_AKiCAbhppk"><span><span><span><strong><span><u><span>…;). There was also a skier triggered avalanche in Lick Creek that was 2-4’ deep (</span></span></span></span></span></span><a href="https://youtube.com/shorts/RBkECAuBzKg?feature=share"><span><span><span…;) and a 2.5’ deep slide was remotely triggered in Fairy Lake (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/27849"><span><span><span><strong><span…;). Triggering avalanches is </span></span></span></span></span></span><span><span><span><span><em><span>very likely</span></em></span></span></span></span><span><span><span><span><span><span> 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. </span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>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 (</span></span></span></span></span></span><span><span><span><strong><span><span>observation </span></span></strong></span></span></span><a href="https://www.mtavalanche.com/node/27848"><span><span><span><strong><span…; </span></span></strong></span></span></span><a href="https://www.mtavalanche.com/node/27843"><span><span><span><strong><span…; </span></span></strong></span></span></span><a href="https://www.mtavalanche.com/node/27840"><span><span><span><strong><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 </span></span></span></span></span></span><span><span><span><span><em><span>before</span></em></span></span></span></span><span><span><span><span><span><span> 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.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>For today, the avalanche danger is rated CONSIDERABLE on all slopes since triggering avalanches is likely.&nbsp;</span></span></span></span></span></span></p>

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

<p><span><span><span><span><span><span>The mountains have dangerous avalanche conditions. A buried weak layer (feathery surface hoar crystals) was avalanching </span></span></span></span></span></span><span><span><span><span><em><span>before</span></em></span></span></span></span><span><span><span><span><span><span> 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.</span></span></span></span></span></span></p>

KING AND QUEEN OF THE RIDGE, FEBRUARY 4TH

Remotely triggered avalanche in Fairy Lake

Fairy Lake
Bridger Range
Code
ASr
Latitude
45.90430
Longitude
-110.95800
Notes

From IG:

Fairy lake today, remote trigger from top of the ridge
 
About 2-2.5ft deep about 75-100 ft wide
 
Number of slides
1
Number caught
0
Number buried
0
Trigger
Skier
Trigger Modifier
r-A remote avalanche released by the indicated trigger
Slab Thickness
30.0 inches
Slab Width
90.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Many naturals, Cooke City

COOKE CITY
Cooke City
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
0
Number buried
0
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year