Good morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Friday, February 13, at 7:30 a.m. The Cooke City Bearclaw and Super 8 in partnership with the Friends of the Avalanche Center sponsors today’s advisory. This advisory does not apply to operating ski areas.
Yesterday high temperatures in the mountains reached the low to mid 40s F, and this morning temperatures had dropped to a few degrees either side of freezing. Westerly winds were blowing 15-30 mph. Today will have more sunshine with temperatures reaching the 40s F again. Winds should ease this afternoon. Some snow should come tomorrow with cooler temperatures.
Wet Snow Danger
With a light freeze overnight and sunshine and warm temperatures today, wet snow avalanches will become possible this afternoon especially with calm winds, and the danger of wet snow avalanches will be MODERATE. Any wet snow avalanche activity that occurs shouldn’t be very big but will be something to watch for. Fortunately the snowpack will give warning signs like pinwheels of snow rolling downslope.
Southern Madison Range Southern Gallatin Range
Lionhead Area near West Yellowstone
The mountains near West Yellowstone have generally stable conditions, but a weak layer of facets and surface hoar is buried 1-2 feet deep on many slopes. Yesterday my partner and I covered about 50 miles riding around Lionhead where we consistently found this layer on slopes containing good powder (video). Eric and I found it in Teepee Basin, and Doug found it in isolated places in the Taylor Fork area last Sunday (video, photo, snowpit profile) the same day a small slide was triggered by a rider. The presence of this layer means human triggered avalanches are possible and the danger is rated MODERATE on all slopes steeper than 35 degrees. Less steep slopes have a LOW avalanche danger.
Bridger Range Northern Madison Range
Northern Gallatin Range Cooke City
In the mountains near Bozeman, Big Sky, and Cooke City, triggering an avalanche is unlikely but not impossible. Wind slabs always remain a concern, but warm temperatures have helped wind slabs stabilize. In the northern Madison and Gallatin Ranges, a weak layer of facets and/or surface hoar exists in isolated places. A skier yesterday near Lone Mountain triggered a small avalanche on this layer on a NE facing slope around 9000 ft. There has been no other avalanche activity on this layer, but it is worth looking for since it is buried about 1 foot deep and only takes a few swipes of the shovel to find it. This layer is a problem only in a few locations; otherwise, the snowpack is generally stable and the avalanche danger is rated LOW.
Eric will issue the next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations drop us a line at mtavalanche@gmail.com or call us at 587-6984.
AVALANCHE EDUCATION and EVENTS
Take a look at our Education Calendar for all classes being offered.
1-hour Avalanche Awareness, Cooke City, Chamber of Commerce, 6:30 p.m., Saturday, February 14.
Snow Science and the Human Factor, Bozeman, MSU Procrastinator Theater, 6-8:00 p.m., Tuesday, February 17. The free event will feature a talk by Powder editor and MSU graduate John Stifter, multimedia presentations on the human factor in avalanche risk, a panel of experts from MSU’s Snow & Avalanche Lab and Gallatin National Forest Avalanche Center, as well as a Q & A session (poster).
Companion Rescue Clinic, Bozeman, REI, 6-8 p.m., Friday, February 20 and 10 a.m.-2 p.m. on Saturday, February 21 (field location TBD). Pre-registration is required: www.rei.com/stores/bozeman.html
1-hour Avalanche Awareness, West Yellowstone, Holiday Inn, 7 p.m., Saturday, February 21.
Companion Rescue Course for Snowmobilers, Cottonwood Drainage, Crazy Mountains, Saturday, February 21, 9:30 a.m. – 2 p.m. Please RSVP to your club officers or to kathrynjbarker@fs.fed.us if you are interested in participating.