23-24

Wet snow instabilities

Date
Activity
Skiing
Snowmobiling

We skied into Frazier Basin from the Fairy Lake road. On north facing slopes the snow was dry. On south facing slopes there was a 1-2" melt freeze crust which was softening on southeast-south facing slopes around 11am-noon. Snow was generally dry below that crust, probably got a little more wet today than yesterday.

We saw a few natural wet loose avalanches run throughout the middle of the day in sunny, steep rocky terrain. There were at least 4 old, deeper avalanche crowns, most of which had been reported and occurred 1-2 weeks ago.

We dug a snowpit on a north facing slope at 8,300'. Snow depth was 140cm and there was weak depth hoar (4F hardness) 30-40cm above the ground, below a 2-3 foot deep hard slab. Compression tests broke on the depth hoar/facets at CT29 and CT(30+1), sudden collapse/Q1. 

Skies were partly cloudy in the morning and cleared with scattered clouds through the day. Wind was calm.

Region
Bridger Range
Location (from list)
Frazier Basin
Observer Name
Alex Marienthal

Avalanche in Taylor’s Fork

Date
Activity
Snowmobiling

Avalanche broke about 400ft wide and slid for 250 ft. 4-2ft deep at the crown

Region
Northern Madison
Location (from list)
Taylor Fork
Observer Name
Riley Welk

Frazier Basin

Date
Activity
Skiing

Snow was dry on North aspects when we got there around 10, and we started seeing a couple of wet loose on solar aspects where the terrain was steeper and rocky at 1130.

Snowpack started getting damp on the surface where we were skiing in the love chutes above Ainger Lake around 1300, on the descent back to the shaft house trailhead we were getting small roller balls and the snowpack was saturated below 6600 by 1430. 

 

Region
Bridger Range
Location (from list)
Frazier Basin
Observer Name
Jackson N.

Avalanche on Arden Peak

Date
Activity
Skiing

saw this massive slide that spanned between the "Fat Maid" peak and all the way across Arden from the summit of Palace Butte yesterday.

 

 

 

Region
Northern Gallatin
Observer Name
Paul Neubauer

GNFAC Avalanche Forecast for Sat Mar 16, 2024

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>Changes in the snowpack make us nervous and the warmup that’s happening right now is a significant change. It’s going to be around 5 degrees warmer today than yesterday, when mountain temperatures already climbed above freezing. With this, we expect to see more melting of the surface snow. When formerly dry snow gets wet for the first time it can make it easier to trigger avalanches breaking on deeper weak layers. The uncertainty is high on this, but this season’s snowpack has surprised us time and time again with what small changes it takes to trigger big slides. Don’t let it surprise you today, make a conservative plan and stick to it. Take a minute to look at the pictures and videos of the large slides over the last week and reflect on the catastrophic nature of these avalanches (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31460"><span><span><span><strong><span… details</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31432"><span><span><span><strong><span… video</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://youtu.be/ZaqRmvvNp9c"><span><span><span><strong><span><u><span>… video</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31343"><span><span><span><strong><span… photos</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/snow-observations-list?field_regions_simila… City activity list</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>Smaller slides may also break in wind drifts that formed from the snow that fell mid-week that has now been drifted by unusual east winds. Loose wet avalanches are also expected on sunny slopes today, but shouldn’t be at the forefront of your mind, because you should already be planning on avoiding steep slopes so you don’t trigger a huge, 3 to 12 ft thick, deep slab avalanche breaking near the ground!&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Human triggered avalanches are likely and the avalanche danger is CONSIDERABLE.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>In the Bridger Range, and Lionhead and Island Park areas, the general snowpack structure is similar and the set of concerns are the same, but triggering a big slide is a bit less likely. In the southern areas the weak layers are getting buried deep enough that it’s getting harder to trigger slides and in the Bridgers there has been less loading.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Thinking about getting into steep terrain isn’t unreasonable in these areas, but set yourself up for success by considering both the possibility of triggering a large, deep slide and the more likely case of triggering a smaller wind slab or wet loose avalanche as the day heats up. Paying close attention to the surface snow will give you a good idea about the likelihood of these shallower instabilities. Watch for terrain with rocks, cliffs, gullies, or trees beneath you that would magnify the consequences of one of these smaller slides. Good travel practices (traveling one at a time, wearing rescue gear, and watching your partner from a safe spot) are the best answer to the possibility of getting surprised by a big slide.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Human-triggered avalanches are possible and the avalanche danger is rated MODERATE.</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.