GNFAC Avalanche Forecast for Fri Mar 31, 2023

Not the Current Forecast

Good morning. This is Ian Hoyer with the Gallatin National Forest Avalanche Forecast on Friday, March 31th at 6:45 a.m. This information is sponsored by Blitz Motorsports and Yamaha and Spark R&D. This forecast does not apply to operating ski areas.

Mountain Weather

A trace to 3” of new snow fell yesterday morning. Winds are 10-20 mph out of the SW-W with gusts of 15-25 mph. Temperatures are in the teens F this morning and will rise into the 20s and 30s F this afternoon. Moderate SW-W winds will continue. Snow showers today and tonight will bring 1-2” of new snow tomorrow morning.

Snowpack and Avalanche Discussion

There are two very different sets of avalanche concerns today - avalanches breaking  in the upper couple feet of the snowpack and avalanches breaking deep on weak layers buried months ago. 

Avalanches in the upper snowpack can be triggered beneath the snow that fell over the last week, particularly where it’s been more recently drifted by the wind. In some places the new snow buried a layer of facets that will keep the snowpack from stabilizing as quickly (Throne video). Watch out for shooting cracks as a clear sign of instability and dig down around 3 ft to test the upper snowpack before riding any steep slopes.

A harder to identify, but scarier possibility is triggering a deep slab avalanche. Yesterday, a snowboarder triggered a slide that broke deep in the Lone Lake Cirque, near Big Sky resort, and was carried close to a thousand vertical feet over rocks and huge cliffs (photo). Remarkably he wasn’t buried and survived unscathed. Before this incident, the last deep slabs were triggered a week ago in Hyalite and near Cooke City. You’d have to get unlucky to trigger one of these slides today, but if you do, the consequences could be huge. Avalanches in the newer snow could also step down and trigger a deeper slide. Consider the possibility of a huge slide breaking deep in the snowpack before getting into consequential terrain. 

The avalanche danger is rated MODERATE on all slopes. 

Please share avalanche, snowpack or weather observations via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs). 

 

In Island Park, avalanches in the upper snowpack can be triggered beneath the snow that fell over the last week, particularly where it’s been more recently drifted by the wind. A harder to identify, but scarier possibility is triggering a deep slab avalanche. You’d have to get unlucky to trigger one of these slides today, but if you do, the consequences could be huge. Avalanches in the newer snow could also step down and trigger a deeper slide.

Upcoming Avalanche Education and Events

Events and Education Calendar.

 Friday, March 31, (TODAY) 8 p.m. Hyalite Canyon road closes for motorized use until May 16.

 

The Last Word

Avalanches have killed 23 people in the United States so far this season. On Monday, March 27th, a snowmobiler was killed in an avalanche in Utah. This was the tenth fatality in March. 


More info on each event is available at the Avalanche.org Accidents Page.

 

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