24-25

Isolated Wind Slabs in S. Bridger Range

Date
Activity
Skiing

From email: Isolated wind slabs today in the southern Bridgers.

Region
Bridger Range
Location (from list)
BRIDGER RANGE
Observer Name
Elana Selinger

Small wind slabs on Buck Ridge

Buck Ridge
Northern Madison
Code
SS-AMc-S
Elevation
9000
Aspect
N
Latitude
45.17190
Longitude
-111.38000
Notes

Up to a foot of soft snow which seemed to have included a few inches from last weekend. Winds were transporting snow across Buck Ridge all day long.

We triggered two small and shallow wind slabs that didn't go anywhere, but they were a warning of bigger wind slabs on bigger slopes. We didn't find any faceted or weak layers of concern in the snowpack. 

Wind slabs will grow in size overnight and will be the main concern tomorrow. Fortunately they will be easy to see an avoid.

 

Number of slides
2
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Snowmobile
Trigger Modifier
c-A controlled or intentional release by the indicated trigger
Bed Surface
S - Avalanche released within new snow
Problem Type
Wind Slab
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Buck Ridge

Date
Activity
Snowmobiling

Up to a foot of soft snow which seemed to have included a few inches from last weekend. Winds were transporting snow across Buck Ridge all day long.

We triggered two small and shallow wind slabs that didn't go anywhere, but they were a warning of bigger wind slabs on bigger slopes. We didn't find any faceted or weak layers of concern deeper in the snowpack. 

Wind slabs will grow in size overnight and will be the main concern tomorrow. Fortunately they will be easy to see an avoid.

 

Region
Northern Madison
Location (from list)
Buck Ridge
Observer Name
Staples and Gerardi

Margarets Meadow

Date
Activity
Skiing

Toured into Margaret's Meadow this afternoon. 2" of dense snow over a 1/2 of graupel, on top of a wind crust. Light winds from the SSE. Light wind loading on the N, and NE aspects. No cracking or collapsing, and new snow seems to be bonding (at leas on lesser angled slopes). Skiing conditions were  surprisingly good.

Region
Bridger Range
Location (from list)
Brackett Creek
Observer Name
C. Robinson

GNFAC Avalanche Forecast for Sun Mar 16, 2025

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>Winds have increased to strong from the west and southwest after multiple days of calm conditions. These winds are drifting 10-20” of new snow&nbsp;(1-2" of snow water equivalent) from the last couple days into fresh cohesive slabs up to 2 feet deep. </span></span></span><strong><span><span>Wind slab avalanches</span></span></strong></span></span></span><span><span><span><span><span><span> are easy to trigger and dangerous avalanche conditions will develop. Heavy snowfall is possible today and strong wind will continue, so the size, likelihood and distribution of avalanches will increase through the day.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><strong><span><span>Loose snow avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>and </span></span></span></span></span></span><span><span><span><strong><span><span>storm slab avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>are also possible and can easily run long distances on the crust below the new snow (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=6pLrdFVFpdE&amp;list=PLXu5151nmAvToI_ir…;. These are especially dangerous if they drag you into rocks, trees or over a cliff. On Friday in the Centennials near Island Park Mark saw a larger avalanche that broke on or under the crust below the new snow (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=3ziK29iO3zQ&amp;list=PLXu5151nmAvToI_ir…;

<p><span><span><span><span><span><span>An additional problem south of Big Sky to West Yellowstone are deeper </span></span></span></span></span></span><span><span><span><strong><span><span>persistent slab avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>breaking 2-5 feet deep on the weak snow that was buried in late January. On Friday in Taylor Fork a snowmobiler triggered a 2-3 foot deep hard slab on a short, steep slope with a relatively shallow snowpack (2 to 5’ deep)(</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34610"><span><span><span><strong><span…, photo and obs. from my visit to the avalanche in Taylor Fork yesterday</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). These types of slides have become increasingly less frequent, but we could see more with the added weight of new snow over the next few days.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Today the avalanche danger is CONSIDERABLE. Choose terrain carefully. Avoid steep wind-loaded slopes. Consider avoiding all slopes steeper than 30 degrees as heavy snowfall and strong wind increase the chances of human-triggered and natural avalanches through the day.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Less snow is expected near Bozeman and Big Sky compared to the southern half of our forecast area, and less snow fell over the last couple days (6-16" = 0.7-0.9" snow water equivalent). Strong wind today will create fresh slabs that are easy to trigger, making human-triggered </span></span></span></span></span></span><span><span><span><strong><span><span>wind slab avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>likely. Yesterday there were a couple fresh natural wind slab avalanches reported in the northern Bridgers (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34607"><span><span><span><strong><span…;). Today, wind-loaded slopes could be widespread and the size of slabs will grow due to continuing steady moderate to strong winds. Be on the lookout for fresh drifts on all aspects and elevations, not just the typical areas like near ridgelines.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>On non-wind-loaded slopes </span></span></span></span></span></span><span><span><span><strong><span><span>loose snow avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>are possible and can run long distances on the crust below the recent snow. These can be easy to identify and manage, but can easily knock you over and be dangerous above cliffs, rocks or trees (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34608"><span><span><span><strong><span…’s observation from Bridger Peak</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>).</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Be cautious and avoid wind-loaded slopes today. Watch for a textured or pillowy snow surface, or cracking out from your feet or skis as signs of wind-loading. Avalanche danger is CONSIDERABLE on wind-loaded slopes and MODERATE on other slopes near Bozeman and Big Sky.</span></span></span></span></span></span></p>