24-25

GNFAC Avalanche Forecast for Mon Mar 24, 2025

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>Near Cooke City strong winds have drifted 5” of new snow and snow from last week into stiff slabs that can avalanche under the weight of a person. These </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>are the primary concern, and today the wind will continue to build slabs and create dangerous conditions on wind-loaded slopes. Additionally, a weak layer buried 2 feet deep below last week’s snow can produce larger </span></span></span></span></span></span><span><span><span><strong><span><span>persistent slab</span></span></strong></span></span></span><span><span><span><span><span><span> </span></span></span></span></span></span><span><span><span><strong><span><span>avalanches</span></span></strong><span><span><span>, even on non-wind-loaded slopes. A natural avalanche appeared to break on this layer a couple days ago in Sheep Creek (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/25/natural-avalanche-north-cooke-cit…;), and yesterday Dave and Haylee found it in snowpits with unstable test results (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/25/ectp18-absarokas"><span><span><sp…;, </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=t7oJF2TPrXI&amp;list=PLXu5151nmAvToI_ir…;, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34732"><span><span><span><strong><span…;). Avoid big, wind-loaded slopes and dig down 2-3 feet to assess the snowpack for recently buried weak layers. Be cautious crossing below steep slopes because the recently buried weak layer creates potential to trigger a slide from flatter terrain.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The avalanche danger is CONSIDERABLE on wind-loaded slopes and MODERATE on all other slopes around Cooke City.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Near Bozeman, Big Sky, West Yellowstone and Island Park, </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> are the primary concern where strong winds have drifted last week’s snow into slabs up to a couple feet thick. Be cautious of recently wind-loaded slopes, often identifiable by a textured or rounded snow surface, and typically found near ridgelines below cornices.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Above freezing temperatures, and any rain, will melt the snow surface and make </span></span></span><strong><span><span>wet loose avalanches</span></span></strong><span><span><span> possible. These slides will probably be small today, and most hazardous if they knock you over in terrain above cliffs or rocks. Feel for a moist snow surface as a sign wet snow danger is rising, and find lower angle or colder slopes. </span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Near West Yellowstone, including the southern Madison and southern Gallatin ranges, a person can trigger </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>2-4 feet deep on a weak layer that was buried in January. Avalanches were triggered on this layer in the Taylor Fork on Saturday (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34722"><span><span><span><strong><span…;) and Wednesday (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34697"><span><span><span><strong><span…;). These slides have not been huge, but large enough to be deadly, especially in terrain similar to where they have occurred. They broke on slopes with thick trees that could cause trauma, or depressions at the bottom where snow can pile up deep. Select terrain with minimal terrain traps like trees, cliffs or gullies.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>There is also a chance for slides to break a couple feet deep below last weekend’s snow. Last weekend we saw layers break in stability tests below the new snow near West Yellowstone (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34670"><span><span><span><strong><span…;) and Island Park (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34631"><span><span><span><strong><span…;). Dig down a couple feet to check for potential weak layers.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Human-triggered avalanches are possible and the avalanche danger is MODERATE near Bozeman, Big Sky, West Yellowstone and Island Park.</span></span></span></span></span></span></p>

Natural avalanche north of Cooke City

COOKE CITY
Cooke City
Code
SS-N-R2-D2-O
Elevation
9000
Aspect Range
S-SE
Latitude
45.02020
Longitude
-109.93800
Notes

Photo of a recent natural avalanche north of Cooke City, observed today.  A S, SE aspect in Sheep Creek at about 9000'.   Seems like it likely occurred yesterday.

Estimated to be about 2' deep at 250' wide.

 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
2
D size
2
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
24.0 inches
Vertical Fall
150ft
Slab Width
250.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Photo of a recent natural avalanche north of Cooke City, observed today (3/23/25).  A S, SE aspect in Sheep Creek at about 9000'.  Photo: B Fredlund

 

Cooke City, 2025-03-23

Recent natural avalanche near Cooke City

Date
Activity
Skiing

Photo of a recent natural avalanche north of Cooke City, observed today.  A S, SE aspect in Sheep Creek at about 9000'.   Seems like it likely occurred yesterday.

Estimated to be about 2' deep at 250' wide.

 

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

Wind on Bridger Ridge

Date
Activity
Skiing

Winds were ripping on the hike to Saddle Peak - almost knocking us over. If they had been just a few mph stronger, we would have been crawling. They were still finding snow to transport, and there were obvious plumes at discrete points along the ridge. Much of the snow was being blown to North Dakota while loading only in isolated places. 

As soon as you got off the ridge, winds dropped to almost nothing, and we didn't find any wind slabs as we descended off the nose of Saddle into the North Central Gully. The skiing was excellent.

Further south, the bare rock area north of Bridger Peak had grown significantly as winds scoured a much larger area down to rock.

Region
Bridger Range
Location (from list)
Saddle Peak
Observer Name
Staples