Good morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Thursday, February 2 at 7:30 a.m. A Montana FWP Recreation Trails Grant sponsors today’s advisory. This advisory does not apply to operating ski areas.
Overnight 3-4 inches of dense snow fell in the Bridger Range while all other areas received 2-4 inches of less dense snow. Fortunately winds calmed as snowfall began last night and were blowing 10-15 mph from the NNW this morning with temperatures in the high teens to low 20s F. Lingering snowfall will deposit another 1-2 inches today. Northerly winds will increase to 10-20 mph and will keep temperatures from climbing more than a few degrees.
The southern Madison and southern Gallatin Ranges, the Lionhead area near West Yellowstone and the mountains around Cooke City:
Teaching an advanced avalanche class last night, I stressed that we must always stick to the basics no matter how much we learn about avalanches. Sticking to the basics means never ignoring recent avalanche activity and other obvious signs of instability. Near Daisy Pass outside Cooke City, a snowmobiler triggered a small slide on Tuesday. It was 2 ft deep, 70 ft wide, and 120 ft long. On the same day near the Bacon Rind drainage in the southern Madison Range, Doug and Karl experienced large collapses and shooting cracks (photo, video). Recent storms have kept the snowpack in these areas near its breaking point.
Near Cooke City, the primary weak layer on which avalanches have occurred is buried 2-3 ft deep. Near West Yellowstone, the primary weak layer is buried about 1-1.5 ft deep. Today dangerous avalanche conditions exist, human triggered avalanches are likely, and the danger is CONSIDERABLE.
The Bridger Range and northern Madison Range:
Yesterday, Doug and his partners skied on Saddle Peak in the Bridger Range. They found a snowpack containing all the ingredients for an avalanche (video). What has been missing most of the season is the stress of new snow. Overnight this area received 3-4 inches of dense snow (0.4-0.5 inches of SWE). Is this snowfall enough to make the snowpack unstable? Probably not, but it’s hard to tell. Pay close attention for any cracking or collapsing, dig several snowpits, and chose a conservative line today. The danger could rise if more than a few inches fall or winds increase.
Near Big Sky the snowpack contains plenty of weak snow. On Tuesday, my partner and I rode on Buck Ridge and found avalanches from last weekend on heavily wind loaded slopes. I was able to trigger one last week that broke on facets at the ground, and yesterday the Big Sky Ski Patrol triggered one in an area with a thin snowpack and a wind load. Slopes with this combination are not widespread but do exist on certain terrain features. Today with human triggered avalanches possible, the avalanche danger is MODERATE.
The northern Gallatin Range:
The northern Gallatin Range especially the Hyalite Canyon area has received more consistent snowfall throughout this season. This snowfall has been just enough to build a snowpack lacking widespread weak layers. Unfortunately this area has not escaped recent strong winds which have scoured many slopes and formed hard wind slabs on others. Although triggering one of these wind slabs is not likely, they are the primary avalanche problem. Today, slopes with a wind load or slopes steeper than 35 degrees have a MODERATE avalanche danger. Slopes less than 35 degrees without a wind load have a LOW avalanche danger.
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.
February 4: Poker Run
The Gallatin Valley Snowmobile Association is sponsoring their annual Buck Ridge Poker Ride this Saturday. All proceeds benefit the Friends of the GNFAC. Registration is at 9 a.m. in the Buck Ridge parking lot. More info at www.gvsa.net
February 8: 4th Annual Montana Ale Works Wine Dinner
Come join us for a wonderful, social evening at Montana Ale Works. Menu and ticket information is here: http://bit.ly/wEg01j
February 11: 10th Annual King and Queen of the Ridge
The 10th Annual King and Queen of the Ridge Hike/Ski-a-thon fundraiser is Saturday, Feb 11th. The event supports 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! More Information / Registration Form
Bozeman
FREE 1-hour Avalanche Awareness at REI on Thursday, February 16 at 6:30 p.m. For more information call REI at 406-587-1938