23-24

GNFAC Avalanche Forecast for Mon Mar 4, 2024

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>Avalanche conditions are dangerous, and large, human-triggered avalanches are likely. We have echoed these phrases for the last two months, and it remains important to stay diligent with conservative terrain choices and careful route finding.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>See the </span></span></span></span></span></span><a href="https://www.mtavalanche.com/avalanche-activity"><span><span><span><stro… Log</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span> for a comprehensive review of the long list of avalanche activity from the weekend. Many recent avalanches have been the largest of the season, and some are among the largest we have ever seen on those slopes. Yesterday skiers in Hyalite saw an avalanche that broke thousands of feet wide across an entire basin (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31194"><span><span><span><strong><span…;). Near Cooke City, on Saturday riders watched an avalanche on Henderson Mtn which broke 1000’ wide and ran far into the runout covering multiple fresh snowmobile tracks (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31157"><span><span><span><strong><span…;, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/24/avalanche-henderson-mountain-3"><…;), and yesterday we received photos of big avalanches along the highway 212 snowmobile trail (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31191"><span><span><span><strong><span…;) and near Wolverine Peak (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31199"><span><span><span><strong><span…;).&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Ian and I rode in Tepee Basin on Saturday and saw two recent avalanches that broke 1-2 feet deep (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=byHpBRxx8J8&amp;list=PLXu5151nmAvSH326z…;). Yesterday I went to the northern Bridgers and saw a lot of small slabs and loose snow avalanches in the new snow (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/24/loose-snow-slides-throne-0"><span…;), and saw two slides that were 2-3’ deep and a couple hundred feet wide (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/24/natural-avalanche-south-naya-nuki…;, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/24/natural-avalanche-ross-peak-0"><s…;).</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Avalanches were also seen in the northern Gallatin Range (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31154"><span><span><span><strong><span…;, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/24/rider-triggered-new-snow-slab-030…;), Bacon Rind (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31132"><span><span><span><strong><span…;), Lionhead (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31112"><span><span><span><strong><span…;), and Beehive (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31177"><span><span><span><strong><span…;) over the weekend. Skiers outside the advisory area remotely triggered a slide while ascending a low angle ridgeline above the slope (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31185"><span><span><span><strong><span…; </span></span></strong></span></span></span><a href="https://youtu.be/10mS4ZRTZhY?feature=shared"><span><span><span><strong>…;), and skiers in Hyalite had many whumphs and long shooting cracks (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31161"><span><span><span><strong><span…;).</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Since Thursday 1.5-3 feet of snow equal to 2.1-3.2” of </span></span></span></span></span></span><a href="https://avalanche.org/avalanche-encyclopedia/snowpack/snowpack-observat… water equivalent</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span> (SWE) fell, and over the last week 3-5 feet fell, with the highest amounts near Island Park and Cooke City (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/weather/wx-avalanche-log"><span><span><span… log</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). Yesterday morning in the Bridger Range a rapid storm deposited 15-20” of snow over 6-7 hours (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=5bOHsGISbjQ&amp;list=PLXu5151nmAvSH326z…;). Avalanches can break within or below the recent snow, especially where the wind formed thicker drifts. Additionally, very large avalanches can break on weak snow near the bottom of the snowpack, or on weak layers buried 2-4’ deep below snow from the past week.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>With recent snow and multiple widespread buried weak layers making complex snowpack stability, travel advice is to simply avoid slopes steeper than 30 degrees and flatter runout zones below. Now is not a time to outsmart the snowpack and attempt to find stable, steep slopes. Human triggered avalanches are likely and avalanche danger is CONSIDERABLE.</span></span></span></span></span></span></p>

Upcoming Avalanche Education and Events

Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.

Natural avalanches near Cooke

Date

From IG on 3/3/24. Natural on Wolverine and natural between Miller and Sunset. Looked like they went today or yesterday.

Region
Cooke City
Location (from list)
Wolverine Peak
Observer Name
Zach Dewell

Natural Avalanches on Arden peak

Maid of the Mist
Northern Gallatin
Code
HS-N-R4-D3-O
Elevation
9900
Aspect
E
Latitude
45.41140
Longitude
-110.98800
Notes

Skiers on 03/03/2024 saw several natural avalanches that happened near Maid of the Mist on Arden Peak. These avalanches likely happened between 03/01/2024 and the morning of 03/03/2024

 

From obs on 03/04/2024: "Continued signs of instability on a tour in Maid of the Mist Basin. A couple large collapses down low in the trees, wind slabs above tree line on variable aspects due to swirling wind up high. Large avalanche crown (10’ - 12’ in places) at the back of the basin which looked to have been trigger from cornice fall 3-4 days ago. ECTP 28 55cm off of ground on a 5cm thick layer of facets. Pit was dug on an east facing slope at 9,100 feet."

Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Natural trigger
R size
4
D size
3
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
120.0 inches
Vertical Fall
700ft
Slab Width
1420.00ft
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

From obs: "Shot from the top of Flanders, ~1400 this afternoon, 3/3/2024. Big slide(s) on Arden and in Maid of the Mist. Looks like the skin track and ski track between the two slides got taken out. At first glance from across the way it looked like the skin track was crossing over the debris, but when zoomed in it looks like the debris overran the skin track and the ski track." Photo: M. Zia

Northern Gallatin, 2024-03-03

From obs: "Shot from the top of Flanders, ~1400 this afternoon, 3/3/2024. Big slide(s) on Arden and in Maid of the Mist. Looks like the skin track and ski track between the two slides got taken out. At first glance from across the way it looked like the skin track was crossing over the debris, but when zoomed in it looks like the debris overran the skin track and the ski track." Photo: M. Zia

 

Northern Gallatin, 2024-03-03