Good Morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Advisory issued on Sunday, January 29th at 7:00 a.m. Today’s advisory is sponsored by Cooke City Super 8/Bearclaw Bob’s and Buck Products. This advisory does not apply to operating ski areas.
Temperatures this morning are 20s to low 30s F and wind overnight was out of the west to northwest at 20-30 mph with gusts in the 40s. The mountains have not had any new snow over the last three days. Today will be clear with high clouds and temperatures in the high 20s to 30s F. Wind will be out of the west to northwest at 15-25 mph today, and will increase tonight to 30-40 mph prior to unsettled weather and a chance for snow Monday night.
Bridger Range Madison Range Gallatin Range Cooke City
Lionhead area near West Yellowstone
Wind slabs formed from strong west to northwest wind the past three days are possible to trigger today. The last two days, skiers and snowmobilers triggered 1-2 foot thick wind slabs in the Bridger Range (photo, photo, video), Northern Madison Range (photo), and Cooke City (photo). Minimal snow remains for strong wind yesterday and today to transport and grow slabs. Wind slabs were more difficult to trigger yesterday than on Friday, but are still possible to trigger in steep terrain today. We walked around Bradley’s Meadow north of Bridger yesterday and found wind slabs that ranged from hard and supportable to soft and non-cohesive. These slabs formed over low density new snow and a variety of old snow surfaces. They are most likely to trigger where they rest over sugary facets or low density snow. Approach wind loaded slopes with caution today. Assess the snowpack and evaluate the consequences of the terrain.
Sugary depth hoar near the bottom of the snowpack is still there, but avalanches on this layer are unlikely. It has been over two weeks since the last reported avalanche on this layer. Snow depth in the advisory area ranges from 3-4 feet in the northern ranges to 4-7 feet in the southern ranges. Where the snowpack is deeper, minimal snowfall and wind-loading have allowed weak depth hoar to adjust to overlying slabs. Depth hoar has grown weaker where the snowpack is shallow, but has not had enough load to create an unstable snowpack. Isolated areas where an avalanche could be triggered on this layer are more likely on slopes with varying slab thickness or recent wind loading.
Above freezing temperatures and sunshine today could create wet loose avalanches on sunny aspects. Anticipate changing conditions on sunny slopes through the day. Avoid steep, sunny slopes if the surface is moist or wet.
The avalanche danger today is MODERATE on wind loaded slopes and LOW on non-wind loaded slopes.
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.
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
February 1, Women’s Avalanche Awareness, 6-7:30 p.m., REI Bozeman.
February 7, Sidecountry and Avalanche Awareness, 6-7:30 p.m., Beall Park.
February 8, 1-hr Avalanche Awareness, 7-8 p.m., Roskie Hall, Montana State University.
February 10 and 11, Companion Rescue Clinic, REI and field day, more info and register here.
WEST YELLOWSTONE
February 4 and 11, 1-hr Avalanche Awareness, 7-8 p.m., West Yellowstone Holiday Inn.
COOKE CITY
Weekly rescue training and snowpack update, 6:30-7:30 p.m., Cooke City Super 8 on Friday, Lulu Pass Road for field location Saturday (Look for the yellow sign).
DILLON
February 4 and 5, Intro to Avalanches with Field Day, More info and sign up HERE.
ENNIS
February 17, 1-hr Avalanche Awareness, 6-7 p.m.