22-23

Skinner triggered slide north of the hourglass. Run name unknown. Remotely triggered from ridge line; snowboarder said he was skinning 35 feet away from trigger point; no one buried. I also observed point releases as I was skinning up to texas meadows; snow seemed to change quickly under blue skies and increasing temperature. Slide ran in front of me, taking out the skin track. 

Bridger Range, 2023-04-06

Skier remote trigger in Wolverine Bowl

Wolverine Bowl
Bridger Range
Code
SS-AS-R2-D1.5
Elevation
8000
Aspect
SE
Latitude
45.83010
Longitude
-110.93400
Notes

Skinner triggered slide north of the hourglass. Run name unknown. Remotely triggered from ridge line; snowboarder said he was skinning 35 feet away from trigger point; no one buried. I also observed point releases as I was skinning up to texas meadows; snow seemed to change quickly under blue skies and increasing temperature. Slide ran in front of me, taking out the skin track

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
R size
2
D size
1.5
Problem Type
Persistent Weak Layer
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Skinner triggered slide north of the hourglass. Run name unknown. Remotely triggered from ridge line; snowboarder said he was skinning 35 feet away from trigger point; no one buried. I also observed point releases as I was skinning up to texas meadows; snow seemed to change quickly under blue skies and increasing temperature. Slide ran in front of me, taking out the skin track. 

Bridger Range, 2023-04-06

Skier remotely triggered slide in Wolverine Bowl

Date
Activity
Skiing

Skinner triggered slide north of the hourglass. Run name unknown. Remotely triggered from ridge line; snowboarder said he was skinning 35 feet away from trigger point; no one buried. I also observed point releases as I was skinning up to texas meadows; snow seemed to change quickly under blue skies and increasing temperature. Slide ran in front of me, taking out the skin track. 

Region
Bridger Range
Location (from list)
Wolverine Bowl
Observer Name
Ryan

GNFAC Avalanche Forecast for Wed Apr 5, 2023

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>Although the calendar says “spring” the snowpack says “winter”. I am told spring will be here any day now, but not today. Mountain temperatures are chilly and even with the sun climbing higher in the sky, wet avalanches are not on the menu. Instead we need to keep in mind two avalanche concerns:</span></span></span></span></span></span></p>

<ol>
<li><span><span><span><span><span><span>Avalanches breaking in recent wind drifts 1-2 feet deep, and</span></span></span></span></span></span></li>
<li><span><span><span><span><span><span>Deep slab avalanches breaking 5-6 feet deep from a weak layer that was buried in January.</span></span></span></span></span></span></li>
</ol>

<p><span><span><span><span><span><span>Wind slabs are prevalent. Although a couple days old, slopes with the added weight from wind-loading are our #1 concern. Many avalanches from wind drifting occurred on Sunday, and Dave made a </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=WCGTZlvG5-E"><span><span><span><strong>…; of avalanche activity in Beaver Creek. There were also slides and whumphing reported in the </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28928"><span><span><span><strong><span… Range</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, in </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28941"><span><span><span><strong><span… Basin</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, and near </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28936"><span><span><span><strong><span… City</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Deeper avalanches will be difficult to trigger, but they will be large and deadly. On Sunday, a few deep slab avalanches broke naturally in the Bridger Range at </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28900"><span><span><span><strong><span… Lake</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span> and </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28924%5C"><span><span><span><strong><s… City</span></span></u></span></strong></span></span></span></a><span><span><span><strong><span><span>.</span></span></strong></span></span></span><span><span><span><span><span><span> Dave and Alex were in Lionhead on Monday and saw a deep slab avalanche on Bald Peak which they chronicled in a </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28949"><span><span><span><strong><span…;. Our </span></span></span></span></span></span><a href="https://www.mtavalanche.com/weather/wx-avalanche-log"><span><span><span… and Avalanche Log</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span> list all reported activity. With every substantial snow storm we are seeing big avalanches. Although there are not many of them, they are&nbsp; in every mountain range and will keep us alert well into the spring.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Typically, April is a month of increasing stability from warming temperatures, but not this year, at least not yet. A layered winter snowpack is still with us. For today, avalanches are still possible and I recommend playing on slopes sheltered from the wind. Deep avalanches, although rare, make my palms sweat. Sticking to lower angled terrain or slopes that have clean runout zones is a safer travel strategy than blind luck.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The avalanche danger on all slopes in our forecast area is rated </span></span></span></span></span></span><span><span><span><strong><span><span>MODERATE</span></span></strong></span></span></span><span><span><span><span><span><span>.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Our last daily forecast will be this Sunday, April 9. We will issue weather and avalanche observations every Monday and Friday through April. Please share avalanche, snowpack or weather observations via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).</span></span></span></span></span></span></p>

<p>Wind slabs are prevalent. Although a couple days old, slopes with the added weight from wind-loading are our #1 concern. Deeper avalanches will be difficult to trigger, but they will be large and deadly. With every substantial snow storm we are seeing big avalanches. Although rare, they are in every mountain range. I recommend playing on slopes sheltered from the wind and sticking to lower angled terrain or slopes that have clean runout zones.</p>

Upcoming Avalanche Education and Events

Events and Education Calendar.

Overall seemed like a deep HS (220 cm) versus other years I’ve seen here. High strength in pit (ECTP26), failure on facets below melt-freeze crust down 60 cm, and with no more obvious signs of instability. Felt weak snow deeper, but only dug in the top meter. North winds increasing throughout the day and any wind affected snow was shallow in depth. South aspects were crusted but protected N-facing or tree skiing was still great.

Southern Madison, 2023-04-04

High strength and poor structure at Bacon Rind

Date
Activity
Skiing

Overall seemed like a deep HS (220 cm) versus other years I’ve seen here. High strength in pit (ECTP26), failure on facets below melt-freeze crust down 60 cm, and with no more obvious signs of instability. Felt weak snow deeper, but only dug in the top meter. North winds increasing throughout the day and any wind affected snow was shallow in depth. South aspects were crusted but protected N-facing or tree skiing was still great.

Region
Southern Madison
Location (from list)
Bacon Rind
Observer Name
Antonioli

Sled Triggered Hard Slab Blacktails

Blacktail Mountains
Dillon Area
Code
HS-AMu-R3-D2-O
Elevation
6500
Aspect
NE
Latitude
44.90690
Longitude
-112.36000
Notes

After a long day of riding 2 to 3 thousand feet higher in good snow I was getting close to the truck after 10 or so miles on a mostly hard pack trail I decided to climb this hill in a split second decision. My sled was overheating and my plan was to cool it down. As I ascended the hill I hit a pencil hard wind slab about a third of the way up, I knew instantly that I was in trouble as this slope ended up being much steeper than I had initially thought. I made a decision in the moment to continue up the slope as it was not many vertical feet in elevation. My thoughts were that I had lots of speed and momentum built up and that that would carry me up I also thought that if I tried to make an aggressive turn it would put more stress on the snow pack and I also figured the closer to the top of the slab I was when it fractured the better off I would be. I made it about 100 feet from the top of the hill when it first fractured, I was about 20 feet from the fracture and there was a point slightly to my right that was the closest point of the fracture to me. I turned slightly right heading to the closest point of snow above the fracture line. As I turned the slope started sliding. The top of the of the slide rolled over like a large wave and a block hit me in the ribs luckily not nocking me off my sled. I maintained full throttle and kept my momentum traverseing through the rolling blocks. My only thought was to try to stay on top of my machine and keep forward momentum. In the last few moments of the slide I could feel I was loosing control of my machine because it was starting to get sucked into the avalanche. When the slide stopped I was in snow to my knee on my uphill side. I want to end this with a warning of complacency. I had been in big terrain all day and didn't analyze the slope like I should have a simple glance for a moment and I would have recognized the dangers of the wind slab. I got complacent and it almost got me injured or killed. Just because a slope is small doesn't mean it isn't dangerous.

 

Number of slides
1
Number caught
1
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Snowmobile
Trigger Modifier
u-An unintentional release
R size
3
D size
2
Bed Surface
O - Old snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year