Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, March 2, at 7:00 AM. Today’s advisory is sponsored by Grizzly Outfitters. This advisory does not apply to operating ski areas.
At 6 a.m. snowfall is measuring 4 inches outside Cooke City, 2-3 inches around Taylor Fork and West Yellowstone and 1-2 inches everywhere else. Winds are strong from the west to southwest with gusts of 60 mph and average speeds of 20-30 mph. Under cloudy skies mountain temperatures are in the mid-20s. Winds will remain strong and another 1-2 inches will fall in the south this morning. Skies will be mostly cloudy and temperatures will reach the low 30s.
Southern Madison Range Southern Gallatin Range
Lionhead area near West Yellowstone Cooke City
In the southern mountains, wind and fresh snow will raise the avalanche danger on wind-loaded slopes. The southern mountains have gotten .9-1.2” of snow water equivalency since Saturday which equates to a foot of snow. The wind has been gusty and swirly and loading slopes at all elevations (photo). Additionally, the southern mountains have a weak layer of surface hoar buried 1-2 feet deep (video). The weight of the new snow will keep it unstable. It appears as a stripe in our snowpit wall (photo). We know it is found in every one of our southern ranges but not on every slope. Hunt for it with your shovel and avoid slopes where it exists.
Wind and new snow are creating a CONSIDERABLE avalanche danger on wind-loaded terrain. All other slopes have a MODERATE danger from the widespread distribution of surface hoar.
Bridger Range Northern Madison Range Northern Gallatin Range
In the northern ranges the snowpack is relatively stable (photo). Even so, it’s a good idea to dig and test before committing to avalanche terrain because sometimes the snowpack is different than what we expect. Yesterday, a skier north of Beehive Basin did a quick stability test at 10,000’ on a north-facing slope and was surprised at what he found: a layer of surface hoar was buried a foot deep and propagated fractures (ECTP3) in his stability test. He headed back to his truck. This is the only report of surface hoar in the northern ranges and this is why we dig and test. Slope scale variations require us to be alert for the unexpected. He avoided a potentially dangerous slope and gets a Gold Star for his due diligence.
Winds are still blowing strong and there might be a rogue wind drift that could be triggered. As the skier found, there are slopes harboring weak layers, but they are few and far between, which means it is even more vital to look for them. With generally safe conditions and unlikely chances of triggering slides, the avalanche danger is rated LOW.
Young Alex will issue the next advisory tomorrow morning by 7:30 a.m. If you have any snowpack or avalanche observations to share, drop us a line at mtavalanche@gmail.com or leave a message at 587-6984.
EVENTS and AVALANCHE EDUCATION
A complete calendar of classes can be found HERE.
Bozeman: Wednesday, March 9, 6-7 p.m. 1-hr Avalanche Awareness, REI.