GNFAC Avalanche Forecast for Tue Oct 22, 2019

Not the Current Forecast

This is Dave Zinn with pre-season avalanche, weather, and event information for the Gallatin National Forest Avalanche Center on Tuesday, October 22nd. This information is sponsored by Grizzly Outfitters and Your Montana Chevy Dealers, both supporters of this week’s Powder Blast fundraiser.

Mountain Weather

In the last 24 hours, we received up to 1” of snow in the Northern Ranges and 1-3” in the Southern Ranges, the freezing level is currently around 8000,’ and winds were 10-20 mph from the West.

Mountain winds from the West will increase today into tonight with gusts into the 50s at ridgetops. Temperatures will rise into the 30s before dropping tonight with an approaching cold front. There will be lingering showers this morning with a chance for any additional 1-4” by overnight. Cooke City will get up to 6” of new snow by morning.

We will update our Weather Log and Regional Conditions every morning with snowfall totals, and our Avalanche Activity list if we get a report. The Regional pages have webcams and links to weather stations.

Snowpack and Avalanche Discussion

All Regions

Increasing winds will be the key feature in today’s decision-making puzzle. All the mountains in our forecast area received new snow over the weekend and with 30-40 mph winds forecasted from the West, this snow will move. If you go out today watch for plumes of snow coming over ridges, building cornices, and wind slabs where the blowing snow lands. These are all signs of recent wind loading. Wind slabs generally stabilize within a couple of days but are sensitive when newly formed. Watch for recent avalanche activity, cracking, and collapsing. These indicate instability. Snow water equivalent, take that.

Our secondary avalanche concern is new snow avalanches. Over the weekend up to 21” of snow (2” SWE) blanketed the mountains. You want to know how this new snow is bonding with the old surface. The only way to answer this question is to dig a quick snowpit and perform a stability test. You can dig a snowpit quickly when there is less than 30” of snow on the ground, so, no excuses.

Remember, if it is ski (snowboard, sled, snow angel) season, it is avalanche season. Ice climbers in Hyalite Canyon triggered a small, but potentially consequential avalanche on Sunday (Photo). There is enough snow for an avalanche to drag you across rocks, into trees, and off cliffs. Always carry your avalanche rescue tools and practice safe travel with your partners.

We are preparing for winter, setting up weather stations and beginning to collect snowpack information. If you have avalanche, snowpack or weather observations to share, please submit them via our website, email (, phone (406-587-6984), or Instagram (#gnfacobs).

Upcoming Avalanche Education and Events

Our education calendar is full of awareness lectures and field courses. Check it out and plan to attend one or two: Events and Education Calendar.

Get tickets for the 21st Annual Powder Blast Fundraiser on October 25th at The Emerson Ballroom.


6 November, 1-hr Avalanche Awareness, 6-7pm @ REI Bozeman.

7 November, 1-hr Avalanche Awareness, 6-7pm @ Langford Hall, MSU.

12 November, 1-hr Avalanche Awareness, 6-7pm @ Montana Ski Tuning and Boot Fitters.

14 November, 1-hr Avalanche Awareness, 6-7pm @ South Hedges Hall, MSU.

14 November, 1-hr Avalanche Awareness, 6-7pm @ Uphill Pursuits.

20 November, 1-hr Avalanche Awareness, 6-7pm @ The Mountain Project.

4 & 5 December, Introduction to Avalanche w/ Field Course, Evenings of December 4 & 5 plus one field day either December 7, 8 or 14. Snowmobile specific field day offered December 14. More info and Register Here.


6 November, 1-hr Avalanche Awareness, 6-7pm @ The Base Camp in Helena.

23 November, Helena Snowdrifters, Avalanche Awareness and Partner Rescue Training, 9am-3pm at the Mako Building in Helena


19 November, 1-hr Avalanche Awareness, 6-7pm @ The Base Camp in Billings.

The Last Word

Get tickets for the 21st Annual Powder Blast Fundraiser on October 25th at The Emerson Ballroom.