Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Center’s early season avalanche information issued on Saturday, November 26 at 7:30 a.m. Today’s bulletin is sponsored by Grizzly Outfitters in cooperation with the Friends of the Avalanche Center. We will update this information Monday morning.
At 5 a.m. there’s no new snow to report, just unseasonably warm temperatures and decreasing winds. Winds are west to southwest at 15-20 mph with gusts hitting 40 mph and mountain temperatures in the high 20s under clearing skies. Today will be sunny and unseasonably warm with higher elevations reaching 40F. Sunday will be mostly cloudy and colder with scattered snow showers that evening and Monday.
Check out our new button that displays the previous week’s weather and avalanche activity:
Bridger Range Madison Range Gallatin Range Lionhead area near West Yellowstone
From the Bridger Range to West Yellowstone snow depths range from 10-20”. Snow is deeper in wind-loaded gullies and under ridgelines which is also where a person is most likely to trigger an avalanche. Over the last 48 hours a skier was caught in a slide on a wind-loaded slope in Sacajewea Bowl in the Bridger Range (photo, wind1, wind2); two climbers saw a small avalanche on a wind-loaded shoulder on the Sphinx and prudently did not continue across the exposed north face; skiers in Beehive Basin near Big Sky found sugary, faceted snow capped with wind slabs that cracked with a bit of jumping (a sign of instability) (photo1, photo2); the Big Sky Ski Patrol trigged avalanches in the new, windblown snow.
The 6-8” of new snow that fell Wednesday night has been blown into wind slabs. Decreasing wind speeds and today’s unseasonably warm temperatures will make it harder than yesterday to trigger these slabs, but not impossible. A layer or two of larger grained facets are preserved under the blanket of new snow and will likely need more loading to become unstable.
Cooke City
The mountains around Cooke City have 30 inches of snow. A skier saw 3 natural slab avalanches on the east side of Miller ridge yesterday ranging from 75-200 feet wide. All were wind-loaded slopes. The snowpack has weak layers of facets sandwiched between denser layers (snowpit profile) which may become a problem with more snowfall. In the meantime, wind-loaded slopes are the ones to avoid.
We will update this bulletin Monday morning and issue daily advisories and danger ratings when we get more snow.
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.
BOZEMAN
30 Nov. and 1 Dec., Introduction to Avalanches with Field Course, 7-9:30 p.m. at MSU Sub Ballroom B: Sign up HERE.
6 December, Avalanche Awareness, 6-7:30 p.m. at MSU with Backcountry Squatters Ski Club, SUB Procrastinator Theater.
7 December, Avalanche Awareness, 6-7:30 p.m. at REI.
15 December, Avalanche Awareness and Beacon Practice, 6-8 p.m. at Beall Park.
HELENA
8 December, Avalanche Awareness, 6-7:30 p.m. at The Basecamp.
WEST YELLOWSTONE
15 and 16 December, Snowmobile Introduction to Avalanches w/ Field Day, West Yellowstone Holiday Inn Conference Hotel. More info and sign up HERE.
COOKE CITY
TODAY, 3 Dec.; 9 Dec. and 10 Dec., Weekly rescue training and snowpack update, Cooke City Chamber of Commerce on Friday and field location TBA on Saturday.