Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, December 3 at 7:30 a.m. Today’s advisory is sponsored by JA Gear and Spark R&D. Backcountry conditions exist within the ski area boundary of Bridger Bowl and this advisory is relevant to that area. All other ski areas are closed to uphill travel.
Yesterday was sunny with light winds out of the west and today will be similar: more sun, calm winds and mountain temperatures in the upper twenties. Clouds will increase tonight from a moist southwest flow, but I’m not expecting any snowfall. By tomorrow morning the temperatures will be unseasonably warm in the valleys and below freezing in the mountains. Looking into my fuzzy crystal ball I do not see any significant snowstorms in the coming week, but then again it’s fuzzy, like my brain at 4 a.m.
Cooke City
Without new snow and only light winds, the snowpack around Cooke City is getting a breather. A layer of weak, faceted snow at the ground was responsible for all the avalanche activity and avalanche warnings. Obvious signs of instability like cracking and collapsing of the snowpack or natural avalanche activity will be absent. However, a lack of these does not indicate stability. The poor snow structure will still allow a person to trigger a slide. I expect the avalanche danger to lessen in the coming days, but it’s a slow process and patience is required.
For today, given the weak an unstable snow at the ground, the recent loading from snow and wind on Sunday and Monday, and the avalanche fatality and deep burial last week, I’m continuing to rate the avalanche danger CONSIDERABLE.
Bridger Range Gallatin Range Madison Range
Lionhead area near West Yellowstone
My partner and I dug a pit up Hyalite yesterday and confirmed that slabs of snow are being supported by weaker, faceted crystals at the ground (snowpit). Our stability test propagated a fracture on this layer (ECTP22) and a skier in the adjacent Flanders drainage found the same. Karl Birkeland toured into Bradley’s Meadow in the Bridger Range and found the opposite: he could not get his stability tests to break (video). This left him scratching his head, especially since Eric and I found instability 48 hours prior (video). This divergence is common as a snowpack gets stronger and becomes more stable. The strengthening process is not a linear progression as some areas become stronger than others at different rates of speed. Given these disparities my uncertainty is higher than I’d like. During these times I lean on quick stability tests to help me decide which slopes are unsafe.
I do not expect any naturals, but it is still possible to trigger a slide given the poor snow structure and propagation of fractures in our stability tests. For today, I’m rating the avalanche danger MODERATE.
Mark 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.
Have a Smartphone or Tablet? The Friends of the Avalanche Center just published two FREE apps so you can get the latest avalanche information, videos and photos: iOS 8 GNFAC App; Android app
AVALANCHE EDUATION and EVENTS
Take a look at our Education Calendar for all our classes being offered.
Avalanche Awareness (1-hour), Wednesday, December 10, 6:30 p.m. at REI, Bozeman
Avalanche Awareness (1-hour), Thursday, December 11, 6 p.m. at Summit Motorsports, Bozeman
Weather Workshop, Thursday, December 11, 6:30 p.m. at REI, Bozeman
Fundraiser at Katabatic Brewing, Tuesday, December 16, 4-8 p.m., Livingston
Avalanche Awareness and Beacon Practice, Wednesday, December 17, 6:30-8:30 p.m. at Beall Park, Bozeman
Snowmobiler Introduction to Avalanches with Field Course
West Yellowstone: Dec 18 and 19, 2014: https://www.ticketriver.com/event/12955
Five hours of lectures are followed by a full day field course. Topics covered include: avalanche terrain recognition, the affect weather has on avalanche hazard, the development of the mountain snowpack, decision making skills, and basic search and rescue procedures