GNFAC Avalanche Forecast for Fri Nov 29, 2019

Not the Current Forecast

Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Forecast on Black Friday, November 29th at 7:00 a.m. Today’s advisory is sponsored by Cooke City Super 8/Bearclaw Bob’s and Uphill Pursuits. Alex will put out another forecast tomorrow morning.

*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

Yesterday it snowed 1-2” in the Bridger Range to Big Sky, while the southern ranges to West Yellowstone and Cooke City got 3-5”. Winds have been moderate at 10-20 mph out of the E-SE and N-NW in the Bridger Range with temperatures in the low teens. This morning another snowstorm will impact our area. Winds will shift to the NW at 10-20 mph and by dawn tomorrow we will see 6-10” of new snow in the northern ranges and 8-12” in the southern mountains. The storm is expected to end late Saturday morning.

Snowpack and Avalanche Discussion

For those of us inclined to take a pass on Black Friday and instead indulge in White Friday, you’ll be much happier because of it. The northern mountains got a light covering of snow (.1” snow water equivalent) with Cooke City getting 3-4” (.3” SWE). Although far apart, the mountains have similarities: 2-3 feet of snow with good stability. Buried layers of facets and crusts that formed in the last 2 months are strong enough to support today’s snowfall. However, the new snow will be prone to avalanche at the snow surface where crusts or weak snow are found (snowpits). Dave and I had this concern in Cooke City (video) and yesterday a skier saw tiny slides (photo) which indicate that bigger avalanches will be possible with more snow. Stick to lower angled terrain if you see avalanches or find cracks shooting out from your skis or sled.

The snowpack in the southern Madison, southern Gallatin and mountains around West Yellowstone is weak and unstable. Since Wednesday night the mountains have gotten 6-10” of snow that measures .5”-.9” snow water equivalent. Yesterday and today’s snowfall are creating dangerous avalanche conditions. I expect a skier or sledder could trigger an avalanche breaking at the ground. Last week Alex and Dave found a shallow snowpack (6-18”) made entirely of sugary, very weak snow which is now ripe to avalanche (video). Traveling in the backcountry today is not recommended. Dave and I discuss the avalanche potential in Lionhead in Episode 2 of our Dashboard Talks.

We will begin issuing danger ratings soon. We are still gathering snowpack data and welcome your observations, no matter how brief. You can fill out an observation form, email us (mtavalanche@gmail.com), leave a VM at 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 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

TONIGHT! 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