22-23

Near Two Top

Date
Activity
Snowmobiling

Newly formed melt freeze crust near surface and wind slab continuing to form due to current weather conditions. Wind loaded slopes will continue to be a hazard along with PWL's.

Region
Island Park
Location (from list)
Two Top
Observer Name
Cheyenne Rasmussen

Not too stoked on Saddle

Date
Activity
Skiing

We dropped in off the summit and my partner watched me from the top of the first cliff band while I dug below. HS 125cm. I got CT13, Q1 one foot under the surface which coincided with the natural wind slab avalanche from a few days ago. A CT16, Q1 failed one foot under that and a CT19, Q1 broke on the facets/depth hoar about one foot off the ground. Facets were F+ to 4F-. Slabs were 1F to P hardness. I was not happy about it the snow structure or test results. I decided to skin and boot back up to my partner and then head to the ridge. A big load an it’ll avalanche at the ground. It’s not great out there and the bigness of the terrain certainly increased my concern and effected my decision making, as it should. 

Region
Bridger Range
Location (from list)
Saddle Peak
Observer Name
Doug Chabot

ECT & persistent weak layers – Little Ellis summit

Date
Activity
Skiing

Did two extended column tests on the east-facing slope of Little Ellis, both pits being ~20 ft down from the summit. The snow surface was a layer of surface hoar on top of ~12 cm of new snow. Slope angle was roughly 23 degrees and each pit was 75 cm deep.

We were looking for this season's problematic and persistent weak layers in the snowpack and found them quickly. Our first pit produced an ECTP10 and pulled out all the way to the ground (the entire 75 cm slab propagated on top of a sugary layer of snow at the ground-bed surface). We decided to dig a second pit on the same slope to test again and got different but still unstable results. Our second pit produced an ECTP14 on a layer of sugary snow 30-40 cm deep, and then ECTN on the remaining column of snow (potentially due to a varying ground-bed layer of snow between the two pits – most of the snow beneath the fracture in the second pit was just sugar).

We chose to ski the ridge back to the Mount Ellis parking lot for lower-angle turns (which was our plan before digging the pit, but reinforced by our results).

Region
Northern Gallatin
Location (from list)
Mt Ellis

whumpf under high load on south side of Taylor mountain.

Date
Activity
Snowmobiling

Had 7 sleds in a relatively small area on the south facing side of Taylor mountain at about 10k ft.

Group noticed a substantial wumph after sitting for less than a minute.

Don't believe it is cause for serious alarm as a snow pit showed relative stability. Just something we all noticed and talked about and to be aware of as the snow continues to fall.

 

1/3/23

Region
Island Park
Location (from list)
Yale Creek
Observer Name
Andrew

GNFAC Avalanche Forecast for Tue Jan 3, 2023

Snowpack and Avalanche Discussion

<p>With each day that passes without new snow, triggering an avalanche becomes slightly less likely. However, recent events make it clear that large, human-triggered avalanches are possible. While the likelihood decreases, the consequences of triggering an avalanche deep in the snowpack do not.</p>

<p>Yesterday, a group of riders in the Taylor Fork triggered a slide on a small, steep slope that broke 3-5 feet deep on weak snow near the ground (<a href="https://www.mtavalanche.com/node/27474"><strong><span>details and photos</span></strong></a>). Tragically, on the final day of 2022, a rider triggered a fatal avalanche on Crown Butte near Cooke City (<a href="https://www.youtube.com/watch?v=zjGCqBikpRw&amp;list=PLXu5151nmAvTi1DBS…;). A second, human-triggered avalanche in Cooke City broke under the weight of a rider in Sheep Creek (<a href="https://www.youtube.com/watch?v=Tsr8x3PCG3s"><strong><span>video</span>…;, <a href="https://www.mtavalanche.com/node/27426"><strong><span>details</span></s…;). And yesterday, I rode into Lionhead to look at an avalanche that a group of riders triggered, also on December 31 (<a href="https://www.mtavalanche.com/node/27430"><strong><span>video and details</span></strong></a>). While snowmobilers triggered these recent avalanches, it could easily have been a skier, boarder or climber.</p>

<p>Persistent weak layers of sugary facets existing 1-2 feet below the surface and near the bottom of the snowpack on many slopes of the advisory area create this problem. Recent avalanche activity serves as the most reliable predictor of similar events today.</p>

<p>While we focus on large avalanches breaking deep in the snowpack, remember that smaller slides failing within recent and wind-drifted snow similar to the one on Saddle Peak two days ago are dangerous in steep or technical terrain (<a href="https://www.mtavalanche.com/node/27452"><strong><span>details and photo</span></strong></a>).</p>

<p>Give yourself a wide margin for error by treating all slopes over 30 degrees with suspicion, even when there are already tracks on the slope. Before considering travel in steep terrain, carefully assess the snowpack structure by looking for instability related to layers of sugary facets. And always, regardless of the danger, follow safe travel protocols by exposing only one person at a time to steep terrain, watching your partner from a safe location, and carrying avalanche rescue gear.</p>

<p>The danger is rated MODERATE.</p>

<p>Please share avalanche, snowpack or weather observations via our<a href="https://www.mtavalanche.com/node/add/snow_obs"><span&gt; </span></a><a href="https://www.mtavalanche.com/node/add/snow_obs"><strong><span>website</s…;, email (<strong>mtavalanche@gmail.com</strong>), phone (406-587-6984), or Instagram (#gnfacobs). <span><span>&nbsp;</span></span></p>

<p>Triggering avalanches is slightly less likely with each day that passes without new snow. However, large, human-triggered avalanches breaking on persistent weak layers remain possible. Treat slopes over 30 degrees with suspicion, even when there are already tracks. Regardless of the danger, follow safe travel protocols by exposing only one person at a time to steep terrain, watching your partner from a safe location, and carrying avalanche rescue gear.</p>

<p>On New Year’s Day, I rode in Island Park and found persistent weak layers of sugary facets buried in a layer 1.5-2 feet deep and near the bottom of the snowpack (<a href="https://www.youtube.com/watch?v=j54LPGBrmkg&amp;list=PLXu5151nmAvTi1DBS…;). Before considering travel in steep terrain, assess the snowpack structure by looking for layers of sugary facets. If you find instability, avoid avalanche terrain.</p>

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