GNFAC Avalanche Forecast for Thu Nov 28, 2019

Not the Current Forecast

Happy Thanksgiving! This is Doug Chabot with avalanche, weather and event information for the Gallatin National Forest Avalanche Center on Thursday, November 28th. Today’s update is sponsored by Cooke City Motorsports and Werner Wealth Management.

*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

On Monday night the Bridger Range got 3” of new snow and on Tuesday evening 2” fell in Carrot Basin. Last night it snowed again and at 6 a.m. there is 1-2” of new snow in most areas with an additional 5” in Carrot Basin. Today will be snowy with 2-4” falling by tonight. A stronger system will begin early tomorrow through Saturday morning and drop another 2-4” in the northern ranges and 12” around West Yellowstone and Cooke City. Mountain temperatures will remain in the teens. Ridgetop winds, which are currently E-SE at 10-20 mph and gusting to 35 mph, will remain light to moderate and shift to the south.  

We will update our Weather Log and Regional Conditions every morning with snowfall totals, and our Avalanche Activity list if we get a report.

Snowpack and Avalanche Discussion

As we feast on turkey today and leftovers tomorrow, Ms. Winter will be hard at work carpeting the mountains with snow. Not to be unthankful on a day of thanks, but it’s about time! The snowpack around Bozeman, Big Sky and Cooke City is mostly strong and stable. Dave and I spent the last 2 days in Cooke City and found good stability in the 2-3 feet of snow (video 1, video 2, photo). This dovetailed with observations from skiers in Hyalite, Bridger Range and around Big Sky.

Avalanche concerns through Saturday will be limited to the new snow. In some areas it is falling onto a crust and may not adhere well. Other areas may have weak surface snow which could slide. Additionally, wind will drift snow into dense slabs which could be easy to trigger. Avalanche activity, no matter how small, is a sign of instability, as are cracks shooting out from your skis or sled. Avoid slopes with similar aspect and elevation if you see these signs.

The snowpack south of Big Sky to West Yellowstone is shallow and weak. Alex and Dave walked and skied into Lionhead a week ago and found 6-18” of snow on the ground, all of it faceted. Faceted snow is unsupportable, feels like sugar in your hand and is very weak, which Alex shows in his video. In Carrot Basin 7” of snow has fallen (.6” SWE) and I expect the rest of these ranges to catch up to these amounts soon. The snowpack will not be able to support the weight of much new snow. The avalanche danger is rising and we are prepared for a possible Avalanche Warning if the weather forecast holds true. A foot or more of snow (1” SWE) would make for very dangerous and widespread avalanche conditions. Traveling in the backcountry during the storm is not recommended. We discuss this situation in Episode 2 of our Dashboard Talks.

We are working hard to get out in the field to collect information about the snowpack and we want you to help us by submitting an observation form. Your observations are critical to us developing a complete picture of what is happening in the mountains. You can also email us (mtavalanche@gmail.com), leave a message on our phone (406-587-6984) or Instagram (#gnfacobs).

Dashboard Talks

Episode 1: On our drive back from Cooke City, Dave and I discuss what we look for when we go to an area for the first time.

Episode 2: Dave explains why the snow is so unstable in West Yellowstone.

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.

COOKE CITY

29 & 30 November. Every Friday and Saturday, Snowpack Update and Rescue Training. Friday, 6:30-7:30 p.m. at the Soda Butte Lodge. Saturday anytime between 10-2 @ Round Lake.

BOZEMAN

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.

December 11, 1-hr Avalanche Awareness, 6-7 p.m. at REI.

December 12, Avalanche Awareness + Beacon Practice, 6-8 p.m. at Story Mill Community Center.

WEST YELLOWSTONE

9 & 10 December, Snowmobile/Ski Introduction to Avalanche w/ Field Course, 12-5p Dec 9 and field day Dec 10. More info and Register Here.

MANHATTAN

December 9, 1-hr Avalanche Awareness, 7-8 p.m. at Manhattan High School.

The Last Word

We have many avalanche classes on the calendar. Check to see if one is being offered near you.

Audio File