Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, January 24 at 7:30 a.m. Indulgence and Grizzly Outfitters in partnership with the Friends of the Avalanche Center sponsors today’s advisory. This advisory does not apply to operating ski areas.
Snowfall yesterday afternoon dropped six inches around Big Sky and 2-3 inches everywhere else. Ridgetop winds have been blowing west to northwest at 15-20 mph with gusts to 30 mph. Mountain temperatures are in the single digits under clear skies. Today will be sunny, but cloud up later this afternoon as winds increase to 20-30 mph from the southwest. Temperatures will warm into the 20s this afternoon and drop to the teens tonight. By morning 1-2 inches will fall in the southern mountains with scattered and more widespread showers expected through Wednesday.
The southern Madison and southern Gallatin Ranges, Lionhead area near West Yellowstone and mountains around Cooke City:
Even though the weekend avalanche warning in the southern mountains expired, this area still remains quite active. Outside Cooke City yesterday a snowmobiler was buried in an avalanche on Scotch Bonnet near Lulu Pass (photo). Luckily his arm was sticking out of the snow and nearby skiers dug him out. This near miss is just one of a string. On Saturday, a massive slide on Scotch Bonnet was triggered from hundreds of feet away and later that same day a snowmobiler was partially buried on Henderson Mountain in an avalanche he triggered and was unable to outrun. Mark was there and posted a video and picture of the activity. On Sunday, a snowboarder triggered a slide near Lulu pass on a south facing slope and released another slide sympathetically. A layer of small-grained facets buried under four feet of new snow since last Monday (5” SWE) is the unstable weak layer.
In Lionhead on Sunday, there were multiple avalanches remotely triggered by snowmobilers. One notable slide broke on a low angle 30 degree slope from 300 feet away. Yesterday, another natural avalanche was seen in Cabin Creek by Ace Powder Guides. Weak, large-grained sugary snow is breaking a foot or two off the ground from the recent snows.
The avalanche warning this weekend denoted hair-trigger conditions with many avalanches releasing naturally or being triggered from afar. Things have improved since then, but only slightly. Touchy, dangerous conditions still exist in the southern mountains. A few inches of new snow with winds will keep the backcountry dangerous. For today, the avalanche danger is rated HIGH on all wind-loaded slopes and CONSIDERABLE elsewhere. Unfortunately, around Cooke City the more popular lines to ride or ski are usually wind-loaded.
The Bridger and northern Madison Ranges:
In the Bridger Range a couple inches of new snow with westerly winds blowing 20-30 mph is enough to keep the weak layers in the snowpack under stress. A foot of new snow by Sunday morning broke avalanches loose in the Frazier/Fairy Lake area. The snow structure is weak (snowpit) and stability on wind-loaded slopes is suspect. Eric and his partner skied into the Throne area on Sunday. He turned around and retreated as the slope steepened, a telling sign as any stability test.
In the last 24 hours the mountains around Big Sky got six inches of snow with wind. I dug four snowpits in the Beehive/Bear Basin area on Sunday and found a snowpack that was strengthening, but not quite healed. As my video shows, the facets near the ground still break on facets and depth hoar.
For today, the avalanche danger is CONSIDERABLE on all wind-loaded slopes and MODERATE elsewhere.
The northern Gallatin Range:
During the last five days the northern Gallatin Range has picked up only five inches of snow, not enough to bump the danger upward. The snowpack is generally strong in the Hyalite area with weaker snows found around Mt. Ellis and Little Bear. Yesterday, a snowboarder on Mt. Ellis found facets in the lower half of the snowpack capped by a wind slab at the higher elevation. He descended a conservative line. Since avalanches are still possible, the danger is rated MODERATE.
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.
Watch an eye-opening 20 second video of a small, innocuous slope avalanching and burying a snowmobiler.
Events/Education
Bozeman
Introduction to Avalanches with Field Course. MSU, SUB Ballroom C, 7-9:30 p.m. Jan 25 and 26 with a field day Jan 28.
Advanced Avalanche Workshop with Field Course. MSU, Wednesday and Thursday, February 1 and 2 from 7-9:00 p.m. with a field day Saturday, February 4. Advanced registration is required.
Helena
1-hour Avalanche Awareness lecture at Exploration Works on Tuesday, January 31 at 6:30 p.m. Call 457-1800 or check our calendar for more information.
Dillon
Snowmobiler Introduction to Avalanches with Field Course. Lectures on Saturday, February 4 with a field day Sunday, February 5. Advanced registration is required.