GNFAC Avalanche Forecast for Fri Mar 20, 2020

Not the Current Forecast

Good Morning. This is Ian Hoyer with the Gallatin National Forest Avalanche Forecast on Friday, March 20th at 7:30 a.m. Today’s forecast is sponsored by Yellowstone Artic Yamaha and Montana Alpine Guides.

* Ski Areas are closed for the season. Backcountry conditions exist. There is no avalanche control or ski patrol services. Please stay clear of workers, work areas, snowcats, snowmobiles, chair lifts and other equipment. Watch Dave’s video explaining what to expect if you tour in the ski area.


Mountain Weather

There is no new snow to report this morning. Temperatures are in the teens F and will rise into the 30s F. Winds this morning are 5-15 mph out of the west to southeast. Light southwesterly winds will continue today. Clouds will break up this morning allowing the sun to poke through, but a few snow flurries are also possible. No significant accumulations are expected.

Snowpack and Avalanche Discussion

All Regions

Across our whole advisory area the snowpack is generally stable, but that will change as the day heats up.

The new snow that fell this week has generally bonded well to the old snow surface. Still, pay attention to this interface and make sure you don’t find an isolated pocket where it hasn’t, especially where the new snow has been blown into deeper drifts. Also, check to see if there is surface hoar hiding under the new snow. Surface hoar (photo) formed in many areas earlier in the week. So far we’ve only had one report of someone finding it buried, near Henderson Mountain north of Cooke City. Get in touch and let us know if you do (or don’t) find it when you’re out today, so we can better map its distribution. In places where was the surface hoar was buried, the new snow will avalanche more easily and take longer to stabilize. Either way, watch for shooting cracks as a clear sign the new snow remains unstable.

With warmer temperatures today and a strong springtime sun, conditions will change rapidly. Watch out for the snow surface becoming sticky and wet. It will only take a few hours of unobscured sun to start melting the snow surface. If you begin to see pinwheels and rollerballs, it’s time to move off of steep sunny slopes. New snow getting direct sun for the first time will slide easily on widespread buried ice crusts (video). These slides won’t break very deep, but could be hazardous in higher consequences terrain where a small slide could push you over rocks and cliffs or into trees.

Yesterday I toured in the northern Bridger’s and found stable avalanche conditions, but difficult and dangerous riding conditions on many aspects (video). Avalanches are only one of many hazards in the mountains. Tweaking your knee in a breakable crust or an uncontrolled fall on firm snow in the morning are also real concerns. Plan ahead so you don’t get stuck deciding between hazardous riding conditions and hazardous avalanche conditions. Always make sure that you have a viable, safe, escape route if your intended plan falls through.

The avalanche danger is LOW this morning, but will rise to MODERATE on sunny slopes as the day heats up and wet avalanches become possible.

If you get out, please send us your observations no matter how brief. You can fill out an observation form, email us (, leave a VM at 406-587-6984, or Instagram (#gnfacobs).

Upcoming Avalanche Education and Events

The GNFAC and Friends avalanche education programs have been cancelled due to the coronavirus. Thank you to all our amazing instructors for a great year of education!

Our education calendar lists awareness lectures and field courses offered by other providers: Events and Education Calendar.

The Last Word

On Sunday, March 15, a sidecountry skier was killed in an avalanche out of bounds at the Pebble Creek Ski area south of Pocatello, Idaho. The Utah Avalanche Center visited the site and along with the Sawtooth Avalanche Center, will publish a report soon. This is the 19 avalanche fatality of the winter.