Good Morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Thursday, March 25, at 7:30 a.m. K2 Café and Deli, in cooperation with the Friends of the Avalanche Center, sponsors today's advisory. This advisory does not apply to operating ski areas.
This morning at 4 a.m. temperatures were in the high teens and low 20s F, and ridgetop winds were blowing 10-20 mph from the S and SW. Today will begin with clear skies, but clouds will start moving over the area after midday with snowfall occurring this evening. High temperatures will be near 30 degrees F with S and SW winds continuing to blow 10-20 mph but increasing late this afternoon. By tomorrow morning 2-4 inches of snow will accumulate in the southern half of the advisory area while 1-3 inches will accumulate in the northern half.
The Bridger, Gallatin and Madison Ranges, the Lionhead area near West Yellowstone, the mountains around Cooke City and the Washburn Range:
The primary avalanche concerns are weak layers buried 1-2 feet deep. Several avalanches have occurred in the Bridger Range on these layers. One occurred just south of Saddle Peak in Argentina Bowl, another on the west side of the Bridger Range in the Bostwick drainage, and one in Frazier Basin yesterday on a north facing slope (photo). Just outside the advisory area in the Gravelly Range, a rider was buried in a small avalanche while playing on a small north facing slope last Sunday. He and his partners were riding one at a time in low consequence terrain, and the buried rider was uncovered in less than 1 minute uninjured (photo1, photo2, photo3). This slide occurred on a combination of buried surface hoar and small facets.
Nearly four weeks without significant snow created variability in these layers that are weaker on some slopes than on others. Fortunately they are not buried deeply, and stability assessments are quick and easy. A more difficult assessment involves large facets near the ground. This layer has not produced avalanches in a few weeks, but it's a persistent layer that could still offer a few nasty surprises before the season ends. These weak layers and recent avalanche activity indicate that human triggered avalanches are definitely possible, and today the avalanche danger is rated MODERATE.
YouTube: Saddle Peak Avalanche Q&A
The Saddle Peak Avalanche Q&A held March 4th at the Bozeman Public Library is now online thanks to the Randy and Kristin Wimberg. The entire 75 minute session can be viewed in two parts. Find it on our Videos Page or here: Part 1, Part 2.
New Beacon Park
The Friends of the Avalanche Center used a donation from Yellowstone Adventures to purchase an avalanche beacon training park in West Yellowstone. You can search for pre-placed beacons switched on/off by a control panel. Look for it by the orange snow fence just south of the old airport (photo).
I will issue the next advisory tomorrow morning at 7:30 a.m. If you get out in the backcountry let us know what you find. You can reach us at 587-6984 or email us at mtavalanche@gmail.com.