22-23

Variable Surfaces-Hellroaring

Date

During the annual setup for the Hellroaring Hut we underestimated the amount of snow based on snotel readings in the area. 18”+ in shaded areas around 7,500’ and < 6”-12” on solar aspects, steep solar aspects were already melting out and bare ground was being exposed. Thick sun crusts we’re already formed on most solar aspects, while shaded regions remained unconsolidated. Lots of surface hoar growth in the meadows. Long story short, it’s good to know the relationship/aspect of the Snotel sites you trust for data mid winter, going forward although wary season snowfall was limited there will likely be some interested surfaces to contend with in the Centennial Range until the snowpack gets deep enough to begin the healing process…

-Sam

Region
Island Park
Location (from list)
Hellroaring Creek
Observer Name
Sam Hansen

GNFAC Avalanche Forecast for Sat Nov 5, 2022

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>Wind and snow are a dangerous combination. In the southern mountains the snowpack doubled in the last 24 hours to 20+ inches. In the northern mountains there was less new snow, but close to 20” is on the ground. Wind will be blowing snow into drifts which will be easy to avalanche. All windloaded slopes should be avoided. Hunters are at risk crossing windblown gullies and skiers are at risk as they search for the deepest snows. I expect to hear of human triggered slides in the next week and hope no one gets caught.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>It is avalanche season which means we treat a 20” snowpack in November as you would a 6 foot deep pack in February. The rules are the same. Go with a partner, analyze the snowpack and carry working rescue gear. Early season has 2 extra hazards: be prepared to get raked over rocks if you get caught in a slide and remember that we are a tad rusty traveling in avalanche terrain.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Your observations are more important than ever this time of year as we get to know this season’s snowpack.&nbsp;</span></span></span></span></span></span></p>

<ul>
<li><a href="https://www.mtavalanche.com/node/add/snow_obs"><span><span><span><stron… your Observations</span></span></u></span></strong></span></span></span></a></li>
<li><a href="https://www.mtavalanche.com/snow-observations-list"><span><span><span><… the Observations</span></span></u></span></strong></span></span></span></a></li>
</ul>

<p><span><span><span><span><span><span>If you get out, please share avalanche, snowpack or weather observations via our </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/add/snow_obs"><span><span><span><stron…;, email (</span></span></span></span></span></span><a href="mailto:mtavalanche@gmail.com"><span><span><span><strong><span><u><span>…;), phone (406-587-6984), or Instagram (#gnfacobs). </span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The Centennial Mountains outside of Island Park received 10” in the last 24 hours doubling the snowpack. Wind will be blowing snow into drifts which will be easy to avalanche. All windloaded slopes should be avoided. Go with a partner, analyze the snowpack and carry working rescue gear. Early season has 2 extra hazards: be prepared to get raked over rocks if you get caught in a slide and remember that we are a tad rusty traveling in avalanche terrain.</span></span></span></span></span></span></p>

Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.

Midday Walk in the Bridgers

Date
Activity
Skiing

Went for a short walk in the Bridgers this afternoon (3-11-2022) for a few turns, and to get eyes on how the snowpack is shaping up. We headed from the base to the terrain above Alpine. In the apron of Hidden Gulley, two small dry loose sluffs were visible. Another dry loose sluff was present further north on the ridge. They all appeared to be natural. A photo has been attached. Deciding the apron was too thin for turns, myself and my partner opted to traverse to Bradley Meadow. 

On the way, we dug a quick pit at about 7500 feet on a shaded NE aspect (photo attached). Close to the ground, mixed forms were present with pretty clear faceting occurring. A stout sun crust capped the old snow. Atop the crust and beneath the new snow was a clear layer of large graupel particles, potentially setting the stage for a weak layer with high spatial variability down the road. Deepest snow depth recorded in a shaded area was approximately 50cm. 

Our primary hazard today was the rocks and stumps associated with early season conditions.

Region
Bridger Range
Location (from list)
Bradley Meadow
Observer Name
Tristan McCutcheon

High Winds in the N Bridgers

Date
Activity
Skiing

Winds blowing hard from the N/NE, 30-40 mph gusts. Graupel falling at start of storm and accumulating fast. Left car at 9am with zero accumulation and returned to 4 inches by 2pm (11/2/22). North facing aspects within the basin had little to no snow left over from the previous storm as slopes were heavily wind scoured. East facing aspects at higher elevations had the most substantial base. Wind loading was observed in large, isolated drifts on top of the Love Chutes and at the rim of Frazier Basin. Snowpack was about 2 feet deep in these drifts with little connection to slopes below.

Region
Bridger Range
Location (from list)
Frazier Basin
Observer Name
Addison Holtzhafer

GNFAC Avalanche Forecast for Thu Nov 3, 2022

Snowpack and Avalanche Discussion

<p>In the last 24 hours, the mountains received 4-7” of snow near Big Sky and Bozeman and 1-3” near West Yellowstone and Cooke City. Today, avoid small loose snow avalanches in all steep terrain and avalanches breaking wider as slabs where the wind loaded slopes with drifted snow before calming this morning. Even a small avalanche will drag a skier or rider through the rocks and result in trauma with our thin, early-season coverage.</p>

<p>As this and subsequent storms load the foundation of the snowpack, assess how the layers of snow develop and interact by watching your surroundings for signs of obvious instability and digging snowpits to test for less obvious instability. A snowy week begins on Friday and the avalanche danger will rise as new snow adds up.</p>

<p>If you get out, please share avalanche, snowpack and weather observations on our <a href="https://www.mtavalanche.com/node/add/snow_obs"><strong><span>website</s…;. If you choose to make them public, they will populate our <a href="https://www.mtavalanche.com/snow-observations-list"><strong><span>NEW OBSERVATIONS PAGE</span></strong></a>. Check out the <a href="https://www.mtavalanche.com/snow-observations-list"><span>snowpack and avalanche observations</span></a> we received after the last storm, including a large natural avalanche in the Headwaters area of Big Sky Resort (<a href="https://www.mtavalanche.com/node/26695"><span>avalanche details</span></a>).</p>

<p>Regardless of whether you are hunting or seeking early-season powder, employ principles of safe travel when in steep snow-covered terrain by having a partner, avoiding steep terrain when signs of instability are present, exposing a maximum of one person at a time to slopes steeper than 30 degrees, and carrying rescue gear that you’ve practiced using (avalanche beacon, shovel, and probe). Early-season avalanches in southwest Montana have injured, buried and killed skiers, riders and hunters (<a href="https://www.mtavalanche.com/accident/12/10/31"><strong><span>2012 Report</span></strong></a>, <a href="https://www.mtavalanche.com/accident/15/11/06"><strong><span>2015 Report</span></strong></a>, <a href="https://www.mtavalanche.com/accident/17/10/12"><strong><span>2017 Report</span></strong></a>).</p>

<p>Beyond utilizing safe travel protocols, <a href="https://www.youtube.com/watch?v=Izkv4IIUmbk&amp;list=PLXu5151nmAvSpq8Ps… the condition of your gear</span></strong></a>, <a href="https://www.youtube.com/watch?v=p1xuaaSq4YU&amp;list=PLXu5151nmAvSpq8Ps… rescue techniques </span></strong></a>and take an avalanche class to further your skills (<a href="https://www.mtavalanche.com/workshops/calendar"><strong><span>education calendar</span></strong></a>).</p>

<p><span>Your observations are more important than ever this time of year as we get to know this season’s snowpack. If you get out, please share avalanche, snowpack or weather observations via our <a href="https://www.mtavalanche.com/node/add/snow_obs"><strong><span>website</s…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><span>mtavalanche@gmail.com</span…;), phone (406-587-6984), or Instagram (#gnfacobs). We’ll update the <a href="https://www.mtavalanche.com/weather/wx-avalanche-log"><strong><span>Wea… and Avalanche Log</span></strong></a> daily and issue pre-season bulletins as needed throughout the fall as conditions warrant. </span></p>

<p><span>The Centennial Mountains outside of Island Park received 5” of new snow. Assess how the layers of snow develop and interact by watching your surroundings for signs of obvious instability and digging snowpits to test for less obvious instability. Today, avoid small loose snow avalanches in all steep terrain and avalanches breaking wider as slabs where the wind loaded slopes with drifted snow before calming this morning. </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.

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