Good morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Thursday, February 13 at 7:30 a.m. A Montana FWP Recreation Trails Grant sponsors today’s advisory. This advisory does not apply to operating ski areas.
AVALANCHE WARNING
The Gallatin National Forest Avalanche Center is continuing a Backcountry Avalanche Warning for the mountains around Cooke City. Heavy snowfall and strong winds have created highly unstable conditions. Natural and human triggered avalanches are very likely. The avalanche danger is rated HIGH in the mountains around Cooke City. Very dangerous avalanche conditions exist. Travel in avalanche terrain is not recommended and avalanche runout zones should be avoided.
This warning will either be terminated or updated by 6:30 AM on Friday, February 14.
Since yesterday morning 10-12 inches of snow fell near Cooke City, 4-5 inches near West Yellowstone, and 2-3 inches near Big Sky while the mountains near Bozeman remained mostly dry. Every place received strong winds which blew 30-40 mph last night with gusts of 60 mph. This morning winds from the SW were blowing 25 mph gusting to 40 mph and temperatures were in the mid 20’s F. Strong winds will continue today and should increase some this afternoon blowing from the W at 30 mph gusting to 50 mph. Temperatures will rise into the upper 20s F and many places should get about an inch of snow today while Cooke City could get 2-4 inches.
Cooke City
Not only have the mountains near Cooke City received a lot of snow and wind, but snow was falling at a rapid rate yesterday. A heavy load combined with rapid loading means avalanches are very likely. My partner and I remotely triggered a slide near the snowmobile entrance to Sheep Creek (photo) on Tuesday. Also on Tuesday, a snowboarder just north of Round Lake triggered and was buried in an avalanche. Yesterday, visibility was limited but the snowpack gave us other clues of unstable conditions. There were small avalanches on road cuts and we could trigger little slides on small rollovers. Other sledders remotely triggered a small slide near Round Lake and saw another larger one nearby.
Heavy snowfall, strong winds, and recent avalanche activity are clear warning signs. Avoid any slope over 30 degrees, even very small ones like road cuts and avoid avalanche run out zones (video). Today both natural and human triggered avalanches are very likely and the avalanche danger is HIGH.
Madison Range Southern Gallatin Range
Lionhead area near West Yellowstone
The mountains from Big Sky to West Yellowstone have received less snow than Cooke City. However the snow is starting to add up and build a cohesive slab on top of a weak layer of facets buried 1.5 to 2 feet deep. In the southern Madison Range yesterday, Eric and Karl experienced large collapses on this layer. Any slope with this weak layer should produce an avalanche. Recent avalanches (read the list in Tuesday’s advisory) are the best proof of more to come. This weak layer exists mostly on open slopes near or below treeline. Slopes at higher elevations may not have this layer but have plenty of fresh wind slabs which should produce an avalanches as well. For these reasons today human triggered avalanches are likely and the avalanche danger is CONSIDERABLE.
Bridger Range Northern Gallatin Range
Less new snow in the Bridger and northern Gallatin Ranges means fewer avalanches. Unfortunately a similar weak layer of facets is buried 1.5 to 2 feet deep on some slopes. On some slopes like ones on Mt Ellis, this layer is stronger and stable. On others like skiers found near Mt Blackmore last weekend, this layer is weak and unstable. Even though the Bridger and northern Gallatin Ranges have not received much new snow, they received plenty of wind and winds slabs should produce avalanches (photo). For today the avalanche danger is rated CONSIDERABLE on all wind-loaded slopes steeper than 35 degrees. All other slopes have a MODERATE danger.
US: Six Avalanche Fatalities since Saturday
From the CAIC website: Avalanches have killed six people in the western US since February 8. Avalanches killed two people in Utah on 2/8 and 2/9. Two separate accidents killed two people in Colorado on 2/10. Two people were killed in a single accident on 2/11 in Oregon.
I 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.
KING AND QUEEN OF THE RIDGE
Saturday, February 15th is the 12th Annual King and Queen of the Ridge Hike/Ski-a-thon fundraiser to support avalanche education in southwest Montana. Collect pledges for one, two or the most ridge hikes you can do in the five hours of competition. 100% of the proceeds go to the Friends of Gallatin National Forest Avalanche Center. Kids and families are encouraged to hike too! Hike as an Individual or Team. Make a Pledge. Sign Up. More Info.
EVENTS/EDUCATION
February 20, BOZEMAN: Thursday, 6:30-8:00 p.m., REI, Women’s Specific Avalanche Awareness lecture. Pre-registration is required: www.rei.com/stores/bozeman.html
February 22, BIG SKY: Saturday, 10 a.m. – 2 p.m., Beehive Basin Trailhead, Companion Rescue Clinic. In partnership with Grizzly Outfitters. Space is limited and pre-registration is required. https://ticketriver.com/event/9964
February 22, WEST YELLOWSTONE: Saturday, 7:00-8:00 p.m., Holiday Inn, 1 –hour Avalanche Awareness for Snowmobilers lecture.
More information our complete calendar of events can be found HERE.