Good morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Saturday, January 26 at 7:30 a.m. Montana Import Group in partnership with the Friends of the Avalanche Center, sponsors today’s advisory. This advisory does not apply to operating ski areas.
Overnight 1-2 inches of snow fell in the mountains around Bozeman, Big Sky and Cooke City. The southern Madison Range and mountains around West Yellowstone picked up 2-3 inches. Morning temperatures are in the mid to upper 20s F and winds are blowing 15-25 from the WSW with gusts reaching upward of 30 mph. Today, light snow is likely in the mountains with an additional 1-2 inches possible by this afternoon. Mountain temperatures will warm into the upper 20s to low 30s F and winds will continue to blow 15-25 from the WSW. A stronger storm system will impact our area starting tonight and should deliver 3-5 inches by tomorrow afternoon.
Cooke City
The mountains around Cooke City act as a catcher's mitt for precipitation. Over the past 48 hours, Fisher Creek Snotel site has recorded five inches of snow - but local observations are indicating nearly twice that amount at higher elevations. Moderate winds out of the WSW will easily transport the low density new snow onto leeward slopes, forming fresh wind slabs. These newly formed slabs are today's primary avalanche concern. Upper elevation slopes leeward to the predominant WSW winds will be the most likely to hold wind deposited snow. Human triggered avalanches will be possible for skiers or riders who venture into wind loaded terrain. Fortunately, mitigating this type of avalanche hazard is fairly simple. The absence of buried weak layers will make human triggered avalanches unlikely on non-wind loaded slopes.
Today, human triggered avalanches are possible on wind loaded slopes which have a MODERATE avalanche danger. Non-wind loaded slopes have a LOW avalanche danger.
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone
The few inches of snow that fell in the mountains around Bozeman, Big Sky and West Yellowstone will help raise spirits but will do little to raise the avalanche hazard. This latest dusting of snow will also do little to erase the variable conditions that have formed over the past few weeks. On Thursday, I visited the west side of the Bridger Range and experienced changing conditions nearly every turn (photo1, photo2). This type of adventure riding now seems to be the norm throughout much of our advisory area.
Similar to most aspects of life – there is a positive and negative to everything. Of course the negative side to a long dry spell is the snow quality stinks, but on the positive side – at least the snowpack is stable. There is the possibility a skier or rider could trigger a small isolated wind slab in steep, upper elevation terrain, which is today’s main avalanche concern.
A future problem: Many sheltered slopes now have a layer of weak facets buried under 1-3 inches of new snow. In the southern Madison Range and mountains near West Yellowstone, wind-sheltered slopes have both a layer of facets and a layer of surface hoar which is now preserved. These layers will likely become a problem when we get more snow.
Today, small avalanches are possible in isolated areas or extreme terrain and the avalanche danger is rated LOW.
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.
OTHER RELEVANT STUFF
No Snow, Big Problem. Read an article on how surface snow can become the next weak layer and future avalanche problem.
Practice using your beacon. The Friends of the Avalanche Center in partnership with the City of Bozeman Recreation Department recently installed a beacon training site at Beall Park on North Black Avenue. It’s free and easy to use.
In Helena, next Thursday (1/31) at 6:30 p.m., the Friends are giving a free 1-hour Avalanche Awareness lecture at Exploration Works (995 Carousel Way).
In Bozeman, on Wednesday, February 6, REI is hosting a 1-hour Avalanche Awareness lecture for Women. Space is limited and registration is required: http://www.rei.com/event/47916/session/64605