GNFAC Avalanche Forecast for Tue Jan 24, 2017

Not the Current Forecast

Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, January 24th at 6:30 a.m. Today’s advisory is sponsored by Grizzly Outfitters in cooperation with the Friends of the Avalanche Center.  This advisory does not apply to operating ski areas.

Mountain Weather

Last night the southern Madison Range (Carrot Basin) picked up 6” of new snow, the Bridger Range got a trace and 1-2” fell elsewhere.  Ridgetop winds are 10-15 mph from the E-NE and mountain temperatures are in the single digits under cloudy skies. Today will warm into the teens, skies will become partly cloudy and easterly winds will remain light. Snow flurries this morning may drop another inch.

Snowpack and Avalanche Discussion

Madison Range   Southern Gallatin Range   Cooke City   Lionhead area near West Yellowstone

Carrot Basin received .4” of snow water equivalent (SWE) totaling 6” of low density powder. The mountains around Big Sky, Lionhead and Cooke City received .1-.2” SWE. This is not much weight and will not increase the avalanche danger. Winds are light and I expect wind slab formation to be minimal.

Today’s stability concerns are with two layers: large, sugary grains of depth hoar at the ground and a layer of facets 2-3’ under the surface. The snowpack is getting stronger which we see in our stability tests (snowpits) and lack of avalanche activity. We are happy to see this trend, but we are still a tad nervous about the weak layer at the ground (video). In our conversations we ask each other, “Would you ski it? Would you ride it?” in reference to known avalanche terrain. Our answers hover around “maybe”, a bit wishy-washy and telling. Triggering an avalanche at the ground would be large and deadly. We believe that on thinner spots of the slope (around edges of the path or near rocky outcroppings) a person might be able to trigger a deep avalanche.  On the upper weak layer, a skier in Beehive Basin got an unstable result in his stability test (ECTP14), a sign that triggering a slide is still possible. For these reasons the avalanche danger is rated MODERATE on all slopes today.

The new snow from the last couple days has buried a surface hoar layer, a weak layer that may produce avalanches with more snowfall (photo, photo).

Bridger Range   Northern Gallatin Range

The mountains around Bozeman are generally stable. We are measuring 2-3 feet of snow on the ground, with conditions ranging from unsupportable sugary facets, to bullet-proof wind slabs and sun crusts. It’s a mixed bag of stable yet highly challenging touring conditions. Eric experienced this first hand near Saddle Peak in the Bridger Range last Wednesday (video), and it’s no better today. The avalanche danger is rated LOW. These mountains also have some surface hoar, but until it gets buried it just remains something pretty to look at (photo).

I will issue the next advisory tomorrow morning by 7:30 a.m.

We rely on your field observations. Send us an email with simple weather and snowpack information along the lines of what you might share with your friends: How much new snow? Was the skiing/riding any good? Did you see any avalanches or signs of instability? Was snow blowing at the ridgelines? If you have snowpit or test data we'll take that too, but this core info is super helpful! Email us at mtavalanche@gmail.com or leave a message at 406-587-6984.

Upcoming Events and Education

Month of January: Montana Ale Works has chosen the Friends of the Avalanche Center as January's "Round It Up America" recipient. Every time you round-up your bill the change gets donated to the Friends. Pennies equal dollars!

King and Queen of the Ridge, Saturday, February 4th. A Hike and Ski/Ride-a-Thon fundraising event to support the Friends of the Gallatin National Forest Avalanche Center. Register with Bridger Bowl HERE, make pledges HERE.

Beacon Training Park at Beall: Open and free to the public for avalanche beacon practice seven days a week from 9 a.m. to 8 p.m., southeast corner of Beall Park in Bozeman.

BOZEMAN

Advanced Avalanche Workshop w/Field Course, 7-9:30 p.m. Thursday and Friday, January 26 and 27 (MSU Sub Ballroom C); field day, Saturday 28th. Sign up HERE.

COOKE CITY

Weekly rescue training and snowpack update, 6-7:30 p.m., The Antlers Lodge on Friday, field location Saturday TBA.

DILLON

February 4 and 5, Intro to Avalanches with Field Day, More info and sign up HERE.

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