24-25

Stabilizing Quickly

Date
Activity
Snowmobiling

We rode Buck Ridge through First Yellowmule, Buck Creek, Second Yellowmule and into McAtee Basin. Pulses of snow through the day dropped an inch or two by the time we left. Light winds, no avalanches, and no signs of instability to report. The measured storm total above the melt-freeze crust was 11" (1.3" of SWE) at the top of 1st Yellowmule. The snow was well bonded to the underlying surface. Quick pits testing the snow above the melt-freeze crust yielded no indicators of instability. 

The riding was quite nice other than the lowest section of the Doe Creek Road is melted out. It was fine on the way in, but very muddy on the way out. 

Triggering an avalanche is unlikely UNLESS:

  1. The wind picks up to speeds capable of transporting snow. 
  2. The temperatures increase or slopes get hit by the warm spring sun. 
  3. There is another significant pulse of snowfall. 
Region
Northern Madison
Location (from list)
Buck Ridge
Observer Name
Zinn and Hoyer

GNFAC Avalanche Forecast for Wed Apr 2, 2025

Snowpack and Avalanche Discussion

<p><span><span><span><strong><span><span>Avalanche Activity:</span></span></strong></span></span></span><span><span><span><span><span><span> Yesterday ski patrols easily triggered soft slab avalanches with ski cuts and explosives. In the Bridger Range where the most snow fell, those slides were much larger and ran surprising distances. Some of these slides broke at the new/old snow interface while others broke on soft layers within the new snow as Dave and Haylee found in the </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34814"><span><span><span><span><span><… Bridgers yesterday</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>. A skier </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34816"><span><span><span><span><span><… Cooke City&nbsp; intentionally triggered a soft slab</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span> on a steep north facing slope.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>There are three avalanche problems to consider today:</span></span></span></span></span></span></p>

<ol>
<li><span><span><span><strong><span><span>Wind slabs</span></span></strong></span></span></span><span><span><span><span><span><span> - The strongest winds happened yesterday morning. Fortunately winds overall have been pretty light. Along upper ridgelines and under cornices, light drifting has created pockets of thick new snow and soft wind slabs. These places will be the most likely spots to trigger an avalanche today, but they are also easy to avoid.</span></span></span></span></span></span></li>
<li><span><span><span><strong><span><span>Storm slabs</span></span></strong></span></span></span><span><span><span><span><span><span> - Since yesterday subtle layers in the new snow have been bonding to each other and to the old snow surface, thus reducing the odds of triggering a soft storm slab avalanche, but we can’t write this problem off just yet.&nbsp;</span></span></span></span></span></span></li>
<li><span><span><span><strong><span><span>Dry loose avalanches or sluffs</span></span></strong></span></span></span><span><span><span><span><span><span> - More snow falling today means there will be some sluffing in the steepest terrain. These types of avalanches typically start at your feet and are mostly a concern for skiers or snowboarders. Making a turn or two and stopping to let the sluff run ahead is one option. Read more </span></span></span></span></span></span><a href="https://avalanche.org/avalanche-encyclopedia/#dry-loose"><span><span><s…;
</ol>

<p><span><span><span><strong><span><span>Travel advice for today:</span></span></strong></span></span></span><span><span><span><span><span><span> </span></span></span></span></span></span><span><span><span><strong><span><span>(1)</span></span></strong></span></span></span><span><span><span><span><span><span> Avoid places at the tops or sides of slopes where winds have drifted some snow making the powder more cohesive and more likely to avalanche. </span></span></span></span></span></span><span><span><span><strong><span><span>(2)</span></span></strong></span></span></span><span><span><span><span><span><span> Watch for any signs like shooting cracks that the new snow is unstable and consider doing some quick tests like Dave shows </span></span></span></span></span></span><a href="https://youtu.be/FxgIax46oPc?feature=shared"><span><span><span><span><s… this video</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>. Jump on </span></span></span></span></span></span><a href="https://avalanche.org/avalanche-encyclopedia/#test-slope"><span><span><… test slopes</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span> and walk/ride above other tracks to get a feel for how the new snow is bonded.&nbsp; </span></span></span></span></span></span><span><span><span><strong><span><span>(3)</span></span></strong></span></span></span><span><span><span><span><span><span> If getting into steeper terrain where getting pushed downhill could be a problem, consider </span></span></span></span></span></span><a href="https://avalanche.org/avalanche-encyclopedia/#dry-loose"><span><span><s… to manage sluffing</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Today the avalanche danger is MODERATE.</span></span></span></span></span></span></p>

Storm/Wind Slab N aspect 9600&#039;, Cooke City

COOKE CITY
Cooke City
Code
SS-ASc-R2-D1.5-S
Elevation
9600
Aspect
N
Latitude
45.02020
Longitude
-109.93800
Notes

From email: "Ski touring near Cooke City today we intentionally triggered a storm slab/ wind slab on a steep north aspect around 9600'.  It was about 6" deep, and 30' wide." 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
Trigger Modifier
c-A controlled or intentional release by the indicated trigger
R size
2
D size
1.5
Bed Surface
S - Avalanche released within new snow
Problem Type
New Snow
Snow Observation Source
Storm/Wind Slab N aspect 9600, Cooke City
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year
24-25

Storm/Wind Slab N aspect 9600, Cooke City

Date
Activity
Skiing

From email: "Ski touring near Cooke City today we intentionally triggered a storm slab/ wind slab on a steep north aspect around 9600'.  It was about 6" deep, and 30' wide." 

Region
Cooke City
Location (from list)
COOKE CITY
Observer Name
B. Fredlund

Well bonded new snow

Date
Activity
Skiing

We skinned up to the Beehive-Bear ridgeline, down into Middle Basin, up Middle Peak and returned the way we came. 

It snowed on and off all day, with little accumulation and patches of sunshine mixed in. Winds were moderate at ridgelines and light-calm lower down. During the periods of sunshine we had good views into Beehive and middle basin. We saw no recent avalanches or signs of instability. 

There were 10-12" of new snow from the last couple days above firm crusts. The new snow had bonded well to the crust. We encountered a little wind drifting at the ridgeline, but it hadn't formed much of a windslab. Loose dry sluffs were the biggest hazard we encountered. The little bit of sunshine densified the snow surface and caused roller balls, but wasn't enough to increase the hazard. 

Region
Northern Madison
Location (from list)
Beehive Basin
Observer Name
Hoyer and Staples

testing

Date
Activity
Snowmobiling

testing

Region
Bridger Range
Observer Name
ian hoyer

Storm Snow in the Bridgers

Date
Activity
Skiing

We headed out to the Bridgers this morning with 13" (1.4" SWE) and more on the way. It may have been April Fool's Day but this was no joke - it is deep out there! We rode out to the Throne and made our way up the East Ridge. On top of the foot of fresh, it snowed around 3-5" in the three hours we were out there.

Our main concerns today were dry loose, storm slab, and wind slab avalanches. We were able to trigger small, loose snow avalanches on steeper slopes in the upper 6" of snow. In one steeper roll over, I got shooting cracks and a small storm slab to break at my ski tips. We did not see other cracking in the recent snow. Visibility was very limited, but we saw one small, filled-in crown near steep, rocky terrain just above the top of the Throne. Winds were blowing all day but were not noticeably drifting snow at mid-elevations. 

When we dug down and performed quick stability tests, we got a mix of ECTNs and propagation (ECTP 10, 11) on a hardness change within the storm snow about 12" deep. We noted this hardness change throughout the day. At lower elevations it was only 3-4" deep, while at upper elevations, closer to a foot. 

Lower down on the E Face, we saw a glide crack that had opened likely after the warm temperatures from last week. 

 

Region
Bridger Range
Location (from list)
The Throne
Observer Name
H. Darby
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