18-19
Cracking and Collapsing in Dudley Creek and Beehive
NORTHERN MADISON RANGE
Northern Madison
Code
Latitude
45.28590
Longitude
-111.28400
Notes
"Wide spread whomping and cracking especially near ridge tops" noted in Dudley Creek on 1/1/2018.
"Ridge lines and wind loaded areas were very touchy and produced small slabs but they seemed isolated to certain slopes." noted in Beehive on 12/31/2018
Number caught
0
Number buried
0
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year
Multiple Slab Avalanches on Crown Butte
Crown Butte
Cooke City
Code
HS-N-R2-D2-O
Latitude
45.05530
Longitude
-109.96000
Notes
Multiple slab avalanches released on Crown Butte in Cooke City on slopes loaded by new snow and wind over the past few days. Photo: T. McCoy
Number caught
0
Number buried
0
Number killed
0
Avalanche Type
Hard slab avalanche
Trigger
Natural trigger
R size
2
D size
2
Bed Surface
O - Old snow
Problem Type
Wind-Drifted Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year
Multiple slab avalanches released on Crown Butte in Cooke City on slopes loaded by new snow and wind over the past few days. Photo: T. McCoy
Avalanche Details: Multiple Slab Avalanches on Crown Butte
Forecast link: GNFAC Avalanche Forecast for Thu Jan 3, 2019GNFAC Avalanche Forecast for Fri Jan 4, 2019
Cooke City, 2019-01-01
Forecast link: GNFAC Avalanche Forecast for Thu Jan 3, 2019GNFAC Avalanche Forecast for Fri Jan 4, 2019
Multiple slab avalanches released on Crown Butte in Cooke City on slopes loaded by new snow and wind over the past few days. Photo: T. McCoy
Avalanche Details: Multiple Slab Avalanches on Crown Butte
Forecast link: GNFAC Avalanche Forecast for Wed Jan 2, 2019
Cooke City, 2019-01-01
Forecast link: GNFAC Avalanche Forecast for Wed Jan 2, 2019
Collapsing and cracking on Mt. Ellis
Mt Ellis
Northern Gallatin
Code
Latitude
45.59250
Longitude
-110.95900
Notes
Eric got a lot of collapsing and cracking as he climbed up through the trees towards the ridge between Little Ellis and Main Ellis. New snow on a shallow and weak snowpack are creating instability.
Number caught
0
Number buried
0
Attached Videos
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year
Natural avalanches in Lionhead
Lionhead Ridge
Lionhead Range
Code
SS-N-R2-D2-O
Aspect
E
Latitude
44.72430
Longitude
-111.32100
Notes
This avalanche in Airplane Bowl off Lionhead Ridge, is south facing at 9,000'. The avalanche was 1-2' deep, 100' vertical and 150' wide (estimated). It likely broke late Sunday or Monday (12/31), during or immediately after the Avalanche Warning. Weak, faceted snow could not support the weekends snowstorm and there were widespread slides. Many of the crowns and debris piles were covered over with wind drifted snow, but there were many slides off the ridge on the facets.
Multiple Avalanches
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
New Snow
Weak Layer Grain type
Faceted Crystals
Attached Videos
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year
This avalanche in Airplane Bowl off Lionhead Ridge, is south facing at 9,000'. The avalanche was 1-2' deep, 100' vertical and 150' wide (estimated). It likely broke late Sunday or Monday (12/31), during or immediately after the Avalanche Warning. Weak, faceted snow could not support the weekends snowstorm and there were widespread slides. Photo: GNFAC
GNFAC Avalanche Forecast for Tue Jan 1, 2019
Snowpack and Avalanche Discussion
<p>The southern mountains, including the Lionhead area had an avalanche warning on Sunday. The snowfall stopped and winds are light, but slopes are still dangerous. Over the weekend the winds blew and 11-18” of snow fell onto an unsupportive snowpack of sugary facets. Near Hebgen Lake on Friday, Alex, Eric, and a separate group of snowmobilers had cracking and collapsing on this layer which was <em>before</em> the storm (<u><strong><a href="https://www.youtube.com/watch?v=MeTYd9mOyGk&list=PLXu5151nmAvRNl9ku…;, <u><strong><a href="https://www.mtavalanche.com/images/18/shallow-weak-unstable-hebgen">pho…;, </u><u><strong><a href="https://www.mtavalanche.com/node/19430">details</a></strong></u>). Triggering slides is likely today, even from flat terrain at the bottom of the slope. Areas that are wind-loaded will be extra prone to triggering. For today, the avalanche danger is rated CONSIDERABLE on all slopes.</p>
<p>In the last four days the northern mountains have gotten 1.5-2 feet of low density snow. The number one sign of instability is recent avalanche activity, with a close second being cracking and collapsing. In the last 48 hours we’ve had nine reports. The <strong><a href="https://www.mtavalanche.com/avalanche-activity">full list</a> </strong>includes the <a href="https://www.mtavalanche.com/node/19466">northern Bridger Range,</a> the <a href="https://www.mtavalanche.com/node/19481">Throne</a>, <a href="https://www.mtavalanche.com/node/19492">Buck Ridge</a>, <a href="https://www.mtavalanche.com/node/19483">Mt. Ellis</a>, <a href="https://www.mtavalanche.com/node/19459">Mt. Blackmore</a>, <a href="https://www.mtavalanche.com/node/19490">Beehive Basin</a>, and the backcountry near the <a href="https://www.mtavalanche.com/node/19488">Yellowstone Club</a>. Most of the activity was confined to new and windblown snow (<strong><a href="https://www.youtube.com/watch?v=nbt8tQ1fmi4&list=PLXu5151nmAvRNl9ku…;). A few slides may have released on facets buried 1.5-2 feet deep (<strong><a href="https://www.youtube.com/watch?v=V_SxEcDhZME&index=2&list=PLXu51…;, <strong><a href="https://www.mtavalanche.com/images/18/ectp-28-n-gallatin">picture</a></…;) while other slopes had a thin and very weak snow structure that was conducive to collapsing (Ellis) and avalanching (Yellowstone Club).</p>
<p>West to north winds are continuing today and forecasted to get even stronger, both at the ridgetops and mid-mountain. Triggering slides on wind-loaded slopes is likely and the danger is rated CONSIDERABLE. On slopes untouched by the wind, the danger is rated MODERATE.</p>
<p>The mountains near Cooke City have received 8-10” of snow over the weekend with remarkably little wind. On Sunday skiers triggered many 2-4” slabs in the new snow in Yellowstone National Park and another skier triggered a small avalanche on Woody ridge (<strong><a href="https://www.mtavalanche.com/node/19475">details</a></strong>). Yesterday, a few natural slides were seen near Lulu Pass (<strong><a href="https://www.mtavalanche.com/node/19484">details</a></strong>) and also on the Fin (<strong><a href="https://www.mtavalanche.com/images/18/natural-avalanche-fin-mt-republic…;). Last week my snowpit on Scotch Bonnet revealed unstable facets 1-1.5 feet below the surface (<u><strong><a href="https://www.youtube.com/watch?v=W6iS9ManzPo&index=2&list=PLXu51…;, <u><strong><a href="https://www.mtavalanche.com/images/18/instability-near-lulu-pass">photo…;) and on Friday a snowmobiler triggered a slide on Mt Abundance on this layer (<u><strong>photo</strong></u>). I also found slopes with less than three feet deep to be exceptionally weak (<u><strong><a href="https://www.youtube.com/watch?v=4Vb2Y4UZJ1Q&index=2&t=0s&li…;), similar to thin snowpacks in other ranges. Given the recent avalanche activity, buried weak layers, and likelihood of increasing wind-loading today, triggering avalanches is possible and the danger is rated MODERATE.</p>
<p>If you get out and have any avalanche or snowpack observations to share, contact us via our <a href="https://www.mtavalanche.com/node/add/snow_observation">website</a>, email (<a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a>), phone (406-587-6984), or Instagram (#gnfacobs).</p>
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
BOZEMAN