Good Morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Friday, January 27th at 7:00 a.m. Today’s advisory is sponsored by World Boards and Edward Jones. This advisory does not apply to operating ski areas.
No new snow has fallen over the past 24 hours. At 5 a.m. temperatures range from the single digits to low teens F under mostly clear skies. Winds out of the W-NW are blowing 5-15 mph in the southern ranges and 15-30 mph in the north. At 4 a.m. Big Sky reported a gust of 51 mph. Today, gusty winds will continue in the northern ranges but remain light to moderate in the south. Temps will warm into the upper teens to low 20s F and skies will remain mostly clear. No new snow is expected over the next 24 hours.
Bridger Range
Two factors play a key role in slab avalanche development - snow and wind. Today, the Bridger Range will have a surplus of both these factors. Fresh snow combined with strong gusty winds will make winds slabs the primary avalanche concern. Winds have blown mainly out of the W-NW, but given the downslope, swirly nature of winds in the Bridgers, I expect slopes on all aspects and elevations to have wind deposited snow. Winds slabs will be resting over a weak foundation, which will make them sensitive to human triggers. Yesterday, a skier on Saddle Peak trigged a soft slab avalanche that broke 6-18” deep, 30’ wide and ran more 1,000 vertical feet (photo). Today, similar avalanches will be likely.
For this reason, the avalanche danger is rated CONSIDERABLE on all wind loaded slopes and MODERATE on non-wind loaded slopes.
Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
For once this season, the mountains south of Bozeman did not pick up as much snow as the Bridger Range. A few inches over the past few days won’t be enough to steadily increase the avalanche hazard. However, strong gusty winds have likely formed a few fresh wind slabs below upper elevation ridgelines. These slabs won’t be large in size, but have the potential to be dangerous in steep, high consequence terrain. Watch for and avoid areas of wind drifted snow.
Outside of the wind slab problem, facets near the ground remain a concern. This layer is getting stronger and has not been stressed in over a weak, which is making it less likely to produce avalanches (video). With that said, depth hoar is notorious for producing unexpected slides, which is a good reason to respect this problem. Doug explains the current situation in a good video from the southern Madison Range (video).
Today, heightened avalanche conditions exist and the avalanche danger is rated MODERATE.
Alex 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.
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.
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.