Good morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Saturday, January 19 at 7:30 a.m. Today’s advisory is sponsored by a Montana FWP Recreation Trails Grant. This advisory does not apply to operating ski areas.
Yesterday winds were gusting 40-60 mph but eased some this morning blowing westerly 10-30 mph. A slight inversion was in place this morning with mountain temperatures near 20 degrees F and valley temperatures in the teens F and just below zero F near West Yellowstone. A NW flow at the leading edge of a ridge of high pressure may bring a few clouds over SW Montana today. Temperatures will climb into the high 20s and low 30s F, and westerly winds will blow 10-30 mph.
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
Yesterday, Eric and I found the last remaining powder in the Bridger Range just north of Bridger Bowl as well as evidence of strong winds from the last few days. We also found a layer of weak, faceted snow buried 6-16 inches deep (snowpit1, snowpit2). A good place to trigger an avalanche is where fresh wind slabs rest on this layer. Fortunately, wind slabs are easy to see and avoid. Also, this layer does not exist on many slopes but slopes that have it shouldn’t be trusted. Finally, looking for and assessing this layer can be done really quickly because it is not buried very deeply. Dig several quick snowpits no more than two feet deep. See how in this video.
Doug was skiing just south of Cooke City yesterday. Although this area mostly lacks a similar layer of facets, he looked for it because it doesn’t take much time and is lurking on a few slopes.
Travel advice today is simple. Avoid fresh drifts and wind slabs, and avoid steep slopes with a layer of weak facets buried 6-16 inches deep. If either problem is encountered, pick a different slope or one less than 30 degrees in steepness. Each of these avalanche problems makes human triggered avalanches possible today and the avalanche danger is rated MODERATE.
Eric 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.
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. It’s free and easy to use.
Learn from recent accidents – On Monday, a skier triggered and was caught and fully buried in an avalanche near Missoula on a slope with thick trees. He was luckily uninjured and quickly dug out by his partner. Report, photos, video