GNFAC Avalanche Forecast for Thu Nov 19, 2020

Not the Current Forecast

Good Morning. This is Alex Marienthal with pre-season avalanche, weather and event information for the Gallatin National Forest Avalanche Center on Thursday, November 19th at 7:30 a.m. This information is sponsored by Grizzly Outfitters and Montana Chevy Dealers. We will issue the next bulletin as conditions warrant.

*Note: Bridger Bowl Ski Area is closed and there is no avalanche control or ski patrol services. Backcountry conditions exist. Workers are setting up for the season and making snow. Please stay clear of work areas, snow guns, chair lifts and other equipment.

Mountain Weather

This morning the mountains near Cooke City and West Yellowstone have 6” of dense new snow and near Bozeman and Big Sky got 2-4”. Temperatures are in the 20s F and wind is west-southwest at 15-20 mph with gusts of 35-50 mph. Today, a few pulses of snow could drop 1-2” near Cooke City and West Yellowstone with less than an inch elsewhere. Temperatures will be in the mid-20s and drop to the teens F overnight. Wind will be west-southwest at 15-30 mph. Over the weekend skies will clear with temperatures in the teens to 20s F, and the next chance for snow is middle of next week.

Snowpack and Avalanche Discussion

All Regions

The mountains throughout our advisory area have a layered snowpack, and avalanches can be triggered on steep slopes. Strong winds drifted last night’s snow into slabs which will continue to grow with strong west-southwest wind today and tomorrow.

Identify and avoid fresh drifts on steep slopes. Expect to find these drifts along ridgelines. Look for signs such as round pillows of snow and feel for relatively hard or hollow slabs. Photos from last week of a skier triggered avalanche (photo) and cracking drifts (photo) are examples of what you might see today and this weekend. Stay diligent with snowpack stability assessment and safe travel protocols through the weekend. If you do ski or ride on steep slopes, assess the consequences of a slide and minimize exposure to trees, cliffs, bare rocks and confined gullies.

Before you go out make sure that all your avalanche rescue gear is in good condition, and practice using it. Watch Dave’s early season videos for tips on checking your gear (video) and practicing with your beacon (video). For more on early season snow conditions you can watch Doug’s 1-hour lecture from a couple weeks ago here.

Every day we will update the weather log, photos page and avalanche activity list.  We will continue issuing early season updates and transition to daily avalanche forecasts when we get more snow. 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

See our education calendar for an up to date list of all local classes. Here are a few select upcoming events and opportunities to check out:

TONIGHT!!!, 6-7 p.m. The Friends of the Avalanche Center will offer a FREE 1-hr Avalanche Awareness Talk. The talk will be a live, ONLINE event. Register here:

December 7-8: Intro to Avalanches w/ Field in West Yellowstone. The 7th is online lectures from 1-5 p.m. and separate snowmobile and ski field days on the 8th. Info and sign up is HERE.

The December Avalanche Fundamentals with Field Course has SOLD OUT, but there will be a second course on January 23 and 24. There are separate field sessions tailored for both skiers and splitboarders (Bridger Bowl) and snowmobilers (Buck Ridge).

Doug spoke with the Last Best Ski Podcast about avalanche fundamentals, some climbing history, and the workings of the GNFAC. The 25-minute podcast is available here.

Support the Friends of the GNFAC

This year, The Friends of the Avalanche Center are unable to host an in-person Powder Blast due to COVID. In place of their biggest fund-raiser, the Friends of GNFAC launched an online GoFundMe campaign. Please consider a donation, and we look forward to having an in-person event again in the future.

The Last Word

The Friends of the Avalanche Center are encouraging everyone to take an avalanche class. Look at our Education Page for all the classes being offered in sw Montana. They are working hard to break down Backcountry Barriers and made this awesome 6 min video about it.