Weather and Avalanche Log for Thu Mar 27, 2025
Air temps above freezing
Clear skies
24-25
GNFAC Avalanche Forecast for Thu Mar 27, 2025
Snowpack and Avalanche Discussion
<p><span><span><span><strong><span><span>Wet loose avalanches</span></span></strong></span></span></span><span><span><span><span><span><span> are the main concern today. Ian describes it well in his </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34766"><span><span><span><span><span><… from yesterday in the northern Bridgers</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span> with aspect, elevation, and timing the three variables to consider. With above freezing air temperatures overnight, the snowpack will only have a superficial refreeze from clear skies. As soon as the surface crust melts, wet sluffs will be possible. </span></span></span></span></span></span></p>
<p><span><span><span><strong><span><span>Pay attention to what’s above you</span></span></strong></span></span></span><span><span><span><span><span><span>. One of the main threats of wet loose avalanches isn’t triggering one, but having one start naturally above you, often near exposed rocks. Another significant concern are large </span></span></span></span></span></span><span><span><span><strong><span><span>CORNICES </span></span></strong></span></span></span><span><span><span><span><span><span>which are more likely to break spontaneously during rapid warm-ups.</span></span></span></span></span></span></p>
<p><span><span><span><strong><span><span>Today</span></span></strong></span></span></span><span><span><span><span><span><span>, I’d only consider riding sunny slopes (east, south, and west) this morning just as they begin to warm and soften. I’d mostly be aiming for upper elevation north facing slopes that still have dry snow. Old wind slabs should mostly be stabilized, but the threat never goes away completely.</span></span></span></span></span></span></p>
<p><span><span><span><strong><span><span>In the Lionhead area, southern Gallatin and Madison Ranges, and mountains near Cooke City to a lesser extent</span></span></strong></span></span></span><span><span><span><span><span><span>, there is a slight chance of triggering a persistent slab avalanche. I’d investigate the snowpack about 3 feet deep especially if going into more extreme terrain where the margin for error is narrow. A slide spotted </span></span></span></span></span></span><a href="https://mtavalanche.com/node/34742"><span><span><span><span><span><u><s… days ago on the Fin above Cooke City </span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>is a good example of this problem.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The avalanche danger today is MODERATE with wet avalanches an issue on slopes receiving direct sunshine at all elevations and shady slopes below treeline where the snowpack is mostly wet.</span></span></span></span></span></span></p>
Wet Loose Avalanches in Airplane Bowl
Fairy Lake
Bridger Range
Code
WL-N-R1-D1-I
Elevation
8500
Aspect Range
S-SE-E
Latitude
45.90430
Longitude
-110.95800
Notes
We rode up to Fairy Lake area today and quickly found out just how warm it has been in this area the last two days. At the trailhead at 10am temperatures were around 47 degrees. Last night, it did not freeze below 9000' and an isothermic snowpack now exists from the trailhead all the way to Fairy Lake and above, until you pop out into Airplane Bowl. When we returned to the trailhead around 2:30pm, it was 65 degrees at the truck.
While higher elevation southerly and easterly snowpacks were warm and wet, free water was only moving through the upper few inches of the snowpack by 1pm. High elevation northerly aspects remained colder and more locked up than we expected given the ambient air temperature. Winds were light from the W and were doing little to keep surfaces cold.
There were a number of wet loose avalanches in Airplane Bowl when we were heading out around 2pm. All on E/S aspects near rocks or cliffs. Most were relatively small and had not entrained much snow from the surface or gouged deeper than a few inches.
On the drive back to town, we noted 5 or so larger wet loose avalanches in Argentina Bowl, with a good number of smaller slides at different points along the ridge
Seeing as it is now the season for wet snow hazards, there are a few things that are critical to consider: aspect, elevation, and timing.
Timing your day to be off of steep slopes before melt water percolates too deep and destabilizes the slope is key, AND making sure to account for steep low-elevation slopes that you may have to pass through on your way back to the trailhead. If you start to sink in deeper than your ankles, or your sled track is digging into slush, that means it is time to either shift to colder aspects or head back to the trailhead.
Our greatest concern with these wet loose avalanches is not so much their size, but their power to push you into terrain traps like cliffs, gullies, trees, or rocks. The two scenarios when we are most concerned about these avalanches are when new snow gets wet and sheds for the first time OR when there have been multiple days without a solid refreeze and melt-water percolates deep into the snowpack.
Number caught
0
Number buried
0
Avalanche Type
Wet loose-snow avalanche
Trigger
Natural trigger
R size
1
D size
1
Bed Surface
I - Interface between new and old snow
Problem Type
Wet Snow
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year
I noticed a couple of wet slides that came off Electric and it’s sun-ridge today. Photo: Anonymous
There were a number of wet loose avalanches in Airplane Bowl. All on E/S aspects near rocks or cliffs. Most were relatively small and had not entrained much snow from the surface or gouged deeper than a few inches. Photo: GNFAC
Avalanche Details: Wet Loose Avalanches in Airplane Bowl
Forecast link: GNFAC Avalanche Forecast for Thu Mar 27, 2025GNFAC Avalanche Forecast for Fri Mar 28, 2025
Bridger Range, 2025-03-26
Forecast link: GNFAC Avalanche Forecast for Thu Mar 27, 2025GNFAC Avalanche Forecast for Fri Mar 28, 2025
There were a number of wet loose avalanches in Airplane Bowl. All on E/S aspects near rocks or cliffs. Most were relatively small and had not entrained much snow from the surface or gouged deeper than a few inches. Photo: GNFAC
Avalanche Details: Wet Loose Avalanches in Airplane Bowl
Bridger Range, 2025-03-26
Wet Snow Season is here
Date
Activity
Skiing
We rode up to Fairy Lake area today and quickly found out just how warm it has been in this area the last two days. At the trailhead at 10am temperatures were around 47 degrees. Last night, it did not freeze below 9000' and an isothermal snowpack now exists from the trailhead all the way to Fairy Lake and above, until you pop out into Airplane Bowl. When we returned to the trailhead around 2:30pm, it was 65 degrees at the truck.
While higher elevation southerly and easterly snowpacks were warm and wet, free water was only moving through the upper few inches of the snowpack by 1pm. High elevation northerly aspects remained colder and more locked up than we expected given the ambient air temperature. Winds were light from the W and were doing little to keep surfaces cold.
There were a number of wet loose avalanches in Airplane Bowl when we were heading out around 2pm. All on E/S aspects near rocks or cliffs. Most were relatively small and had not entrained much snow from the surface or gouged deeper than a few inches.
On the drive back to town, we noted 5 or so larger wet loose avalanches in Argentina Bowl, with a good number of smaller slides at different points along the ridge
Seeing as it is now the season for wet snow hazards, there are a few things that are critical to consider: aspect, elevation, and timing.
Timing your day to be off of steep slopes before melt water percolates too deep and destabilizes the slope is key, AND making sure to account for steep low-elevation slopes that you may have to pass through on your way back to the trailhead. If you start to sink in deeper than your ankles, or your sled track is digging into slush, that means it is time to either shift to colder aspects or head back to the trailhead.
Our greatest concern with these wet loose avalanches is not so much their size, but their power to push you into terrain traps like cliffs, gullies, trees, or rocks. The two scenarios when we are most concerned about these avalanches are when new snow gets wet and sheds for the first time OR when there have been multiple days without a solid refreeze and melt-water percolates deep into the snowpack.
Region
Bridger Range
Location (from list)
Fairy Lake
Observer Name
H Darby
Wet slides
Date
I noticed a couple of wet slides that came off Electric and it’s sun-ridge today
Region
Southern Gallatin
Location (from list)
Electric Peak
GNFAC Avalanche Forecast for Wed Mar 26, 2025
Snowpack and Avalanche Discussion
<p>It will feel like spring today (if not early summer) with temperatures 10 degrees warmer than yesterday and fewer clouds in the sky to block the incoming rays. These conditions will accelerate snow surface warming, and <strong>wet loose avalanches</strong> will pack a serious punch, increasing in volume and traveling farther than yesterday. Southeast through west-facing slopes, and terrain with exposed rocks or cliff bands, will be particularly susceptible as they are exposed to and absorb more heat (<a href="https://www.mtavalanche.com/node/34755"><strong><span>Bradley’s Meadow avalanche</span></strong></a>, <a href="https://www.mtavalanche.com/node/34763"><strong><span>Gallatin Canyon avalanches</span></strong></a>). Yesterday, local ski patrol snow safety teams closed terrain to manage the threat within ski area boundaries. In the backcountry, limit your exposure to problematic aspects and slopes as the snow transitions from frozen and mostly stable to wet and unstable. Move to shadier, northern aspects when the snow surface becomes saturated or you notice warning signs, such as pinwheels or small wet avalanches nearby.</p>
<p>Concern about <strong>wind slab avalanches </strong>has decreased since the last storm ended. However, triggering an unstable drift remains possible, especially on higher elevation slopes below cornices and where the snow remained cool yesterday. Look at photos of wind slab avalanches that broke naturally on Saddle Peak (<a href="https://www.mtavalanche.com/images/25/avalanche-saddle-peak"><strong>ph…;) and in Cooke City yesterday and the day before for examples (<a href="https://www.mtavalanche.com/node/34751"><strong><span>photo and details</span></strong></a>, <a href="https://mtavalanche.com/node/34742"><strong><span>details and photo</span></strong></a>). Avoid obviously wind-loaded slopes or evaluate the upper snowpack for instability. Signs like cracking will not be forthcoming before an avalanche occurs.</p>
<p><strong>Persistent slab avalanches</strong> are less likely, but remain a concern, particularly in the Lionhead, Southern Gallatin, and Southern Madison Ranges, and to a lesser extent, the Cooke City area. Several avalanches broke 2-3 feet deep on buried weak layers within the last week in the Taylor Fork area (<a href="https://www.mtavalanche.com/node/34722"><strong><span>avalanche 1</span></strong></a>, <a href="https://www.mtavalanche.com/node/34697"><strong><span>avalanche 2</span></strong></a>) and north of Cooke City (<a href="https://mtavalanche.com/node/34742"><strong><span>avalanche 3</span></strong></a>). Reduce your risk by selecting smaller slopes without terrain traps and following safe travel practices. Testing the snowpack before entering steep terrain will help you identify instability.</p>
<p>Each avalanche problem demands distinct management strategies, so be mindful of the most pressing threat at any given time. The avalanche danger is MODERATE in the morning but will quickly rise to CONSIDERABLE as wet snow instability intensifies.</p>