23-24

Wet Loose in Beehive

Date
Activity
Skiing

Toured into Beehive Basin on 04/05/2024. Light freeze overnight ~0.5" crust with wet snow below on most slopes. Treed areas did not freeze. Clouds along with a cold south wind kept many slopes from softening. By 11:30 sunny slopes below 9000' had become wet and made for poor ski conditions. Attached are photos of recent loose wet avalanches that likely happened 24-48 hours ago. All attached photos on SW-W aspects at ~9800'

Region
Northern Madison
Location (from list)
Beehive Basin
Observer Name
Zach Peterson

Stiff Crust and New Snow in Lionhead

Date
Activity
Snowmobiling

Today, we rode from the Buttermilk trailhead to Ski Hill then up to Lionhead Ridge.

At the top of Ski Hill, there was a 2" thick supportable crust below 2" of new snow from the last 24 hours. We dug here on a NE-facing slope at 8000', almost the entire snowpack was moist/wet. We had ECTX results in our stability tests. Just to the north of our pit location we saw a small wet loose avalanche that likely happened earlier this week. Along Lionhead Ridge 2-4" of new snow was beginning to form small drifts that were unreactive on test slopes. On the north side of the ridge, we saw areas where portions of cornice had fallen over the last week of warm temperatures. Snow continued on and off through the day with little to no accumulation. West wind remained light throughout the day with moderate gusts. 

Region
Lionhead Range
Location (from list)
Lionhead Ridge
Observer Name
Zach Peterson

GNFAC Avalanche Forecast for Sat Apr 6, 2024

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>There is a good bit of uncertainty today in the avalanche conditions you might encounter, with a mixed bag of wet and dry avalanches possible.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>In most places, wet snow concerns will be minimal because yesterday’s snow surface will either have a hard, thick, refrozen crust, or the snowpack stayed dry through the warmup (on high elevation shady slopes). But, it hasn’t been that cold for that long, so there will still be plenty of places with wet snow in the middle of the snowpack. If the crust is thin, or it gets loaded rapidly by new snow today, you might be able to trigger avalanches in the wet snow beneath. Be wary if you break through a surface crust into wet snow below.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>I expect the little bit of new snow to be generally well bonded to the old snow surface and in many spots the new snow isn’t deep enough to cause a consequential slide. Be on the lookout for places where one or both of those things isn’t true. Pay close attention to how deep drifts are and how well they are bonded. Shooting cracks are a clear sign you’ve found an unstable drift. Stay alert as there is the potential for some short bursts of high intensity snowfall today that could change conditions rapidly.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>New snow also increases the chances of triggering a slide on buried weak layers, particularly those in the upper 1-2 ft of the snowpack</span></span></span></span></span></span><span><span><span><strong><span><span> </span></span></strong></span></span></span><span><span><span><span><span><span>(</span></span></span></span></span></span><a href="https://youtube.com/shorts/SIglDcDu-MU?feature=share"><span><span><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/images/24/fin-cooke-city"><span><span><span… photo</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). Take a few minutes to dig down and test these weak layers before committing to a steep slope. The weak snow at the ground is hard to test and triggering an avalanche down there is unlikely, but still a possibility that should not be entirely forgotten.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The avalanche danger is MODERATE today.</span></span></span></span></span></span></p>

Upcoming Avalanche Education and Events

Hyalite Road Closure: Hyalite road is closed to ALL MOTORIZED VEHICLES until the morning of May 16. This is a regular annual road closure to reduce road damage during the spring thaw. Bicycle and foot traffic are allowed. Contact the Bozeman FS Ranger District for more info.

Hot in the Bridgers

Date
Activity
Skiing

Toured up to fairy lake this morning, found a somewhat frozen snowpack that rapidly warmed. 830am was when we dropped in, @9000 we found a isothermic snow pack that had only around 3-4 of frozen snow over very warm slush. Rockfall started around 900am. 

Region
Bridger Range
Location (from list)
Fairy Lake
Observer Name
Jay Alford

GNFAC Avalanche Forecast for Fri Apr 5, 2024

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>The primary avalanche concern today is wet snow. There may be a light surface crust this morning, but warm temperatures and clouds overnight have kept the snowpack from solidly refreezing. Despite very warm air temps, clouds and cooling winds today will likely keep the wet snow danger mostly in check. However, be on high alert if the sun comes out, even for just a few minutes, especially if winds are light. Thankfully, it’s pretty simple to know when the wet snow danger is rising. If the surface snow gets gloppy, wet and you’re sinking up to your boot tops in wet snow it’s about time to move to shady, cooler aspects or head home. Pinwheels of wet snow and loose slides releasing show the danger has already risen and you should hustle off of steep sunny slopes ASAP.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Slab avalanches breaking on buried weak layers are less likely, but still need mentioning. In many places a thin layer of facets can be found under 1-2 feet of snow from last week. On Monday, snowmobilers in Lionhead triggered a small slide on this layer (</span></span></span></span></span></span><a href="https://youtube.com/shorts/SIglDcDu-MU?feature=share"><span><span><span…;) and it is likely responsible for a natural avalanche on the Fin near Cooke City that broke as the surface snow got wet on Wednesday as well (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/24/fin-cooke-city"><span><span><span…;). The weak snow at the ground is even less likely to avalanche, but if it did, the resulting slides would be very large. Wet loose slides or cornice fall could also help trigger these bigger slides, another great reason to avoid steep slopes that are getting wet.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The avalanche danger is MODERATE today.</span></span></span></span></span></span></p>

Upcoming Avalanche Education and Events

Hyalite Road Closure: Hyalite road is closed to ALL MOTORIZED VEHICLES until the morning of May 16. This is a regular annual road closure to reduce road damage during the spring thaw. Bicycle and foot traffic are allowed. Contact the Bozeman FS Ranger District for more info.

GNFAC Avalanche Forecast for Thu Apr 4, 2024

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>Today’s wet snow avalanche danger is a result of the interplay between temperatures, cloud cover and wind. Yesterday’s unexpected clouds kept most large, wet avalanches at bay. Ian was in Frazier Basin in the Bridger Range, the warmest region, and found the snow surface wetting and sliding (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/24/loose-wet-october-bowl-0402"><spa…;). Even in Cooke City, one of the coolest areas, a few hours of direct sunshine and above freezing temperatures caused a large wet slab avalanche on the Fin on Republic Mountain (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/24/fin-cooke-city"><span><span><span…;).&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>This morning the snow surface is likely frozen, even with above freezing air temperatures. Clouds and wind will keep the wet snow danger in check </span></span></span></span></span></span><span><span><span><span><em><span>IF</span></em></span></span></span></span><span><span><span><span><span><span> the clouds and wind remain as forecasted. That’s a big </span></span></span></span></span></span><span><span><span><span><em><span>IF</span></em></span></span></span></span><span><span><span><span><span><span>. Luckily, identifying conditions for wet snow danger is not subtle. A sign of impending wet danger is when the surface gets gloppy, wet and you can sink to your boot tops. Pinwheels of wet snow and loose slides releasing are another. As Ian pointed out in his </span></span></span></span></span></span><a href="https://youtube.com/shorts/1rWd5PEVNIA?feature=share"><span><span><span…;, seek shady, cooler aspects if this occurs. On Tuesday, Dave had a similar warning and observation after skiing both the west and east side of the Bridger Range (</span></span></span></span></span></span><a href="https://youtu.be/WJWxsKW0flc"><span><span><span><strong><span><u><span>…;).</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Buried in the snow are 2 weak layers we are concerned about. A thin film of facets can be found under 1-2 feet of snow from last week. This is what the Fin likely avalanched on and was the culprit of a small snowmobiler triggered slide Ian and I investigated in Lionhead on Tuesday (</span></span></span></span></span></span><a href="https://youtube.com/shorts/SIglDcDu-MU?feature=share"><span><span><span…;). Much deeper in the snowpack, near the ground, is a thick layer of sugary facets that will not be easily triggered, but man-o-man, if it did, the slide would be deep and big. A cornice peeling off in the warm weather could be an effective trigger (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/24/large-cornices-along-lionhead-rid…;).&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The avalanche danger will start as MODERATE and may rise to a wet snow danger of CONSIDERABLE if the sun comes out and the wind decreases.</span></span></span></span></span></span></p>

Upcoming Avalanche Education and Events

Hyalite Road Closure: Hyalite road is closed to ALL MOTORIZED VEHICLES until the morning of May 16. This is a regular annual road closure to reduce road damage during the spring thaw. Bicycle and foot traffic are allowed. Contact the Bozeman FS Ranger District for more info.