Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, March 9, at 6:45 AM. Today’s advisory is sponsored by Spark R&D and Beartooth Powder Guides. This advisory does not apply to operating ski areas.
Yesterday afternoon’s snowfall was not evenly distributed. Lionhead got the most with 11”, the Big Sky area came in with 6”, and 3” fell in the Bridger Range, up Hyalite, Taylor Fork and Cooke City. West winds spiked into the 20s during the storm and are currently southwest at 10 mph with gusts of 15 mph. Today will be mostly cloudy, winds will slightly increase and temperatures will rise from the mid-teens this morning into the high 20s this afternoon.
Lionhead area near West Yellowstone
The Lionhead area outside West Yellowstone received 11” of new snow which weighed in at .9” of snow water equivalency. My partner and I rode around Lionhead yesterday before the storm hit and we dug four snowpits and saw one small avalanche (photo). We discovered a new weakness: a 2” thick layer of small facets that formed over the weekend and are now buried under 12-18” of snow. This layer will likely avalanche today on any terrain that is wind-loaded or steep. It’s possible that an initial slide on this layer could break 2-feet deeper to the buried surface hoar, which would be tragic if someone was caught. For today, the avalanche danger is rated CONSIDERABLE on all slopes that have been wind-loaded or any slope steeper than 35-degrees. All other avalanche terrain has a MODERATE danger.
Madison Range Southern Gallatin Range Cooke City
The mountains around Big Sky have an elevated avalanche danger from the 6” of snow that fell yesterday. The Big Sky Ski Patrol found the new snow to be “touchy” and reactive to ski cuts. Further south, around Taylor Fork and also outside Cooke City, another problem besides new snow instability is in play: buried surface hoar and/or small, faceted grains buried 2-3 feet deep. Avalanches near Lulu Pass (photo) and Republic Mountain (photo) over the weekend broke on this layer. Alex spent Saturday through Monday there and warns us about lingering instability in his video. Buried weak layers in the southern Madison, Southern Gallatin and Cooke City area, along with new snow instabilities near Big Sky, point to a MODERATE avalanche danger today.
Bridger Range Northern Gallatin Range
The Bridger Range and northern Gallatin Range received 3” of snow. The Bridger Ski Patrol reported the new snow would sluff on the hard bed surface. Skiers in Frazier Basin noted that the snowfall was not wind-loading and they found generally stable conditions. There are occasional slopes that are still showing instability in tests as skiers found on Monday near Ross Peak (photo) when they prudently backed off a steep couloir. Digging before committing to a line is a good tactic no matter the avalanche rating. For today, triggering avalanches is unlikely and the avalanche danger is rated LOW.
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.
TONIGHT, Bozeman: Wednesday, March 9, 6-7 p.m. 1-hr Avalanche Awareness, REI.