Good morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on, Saturday, March 3 at 7:30 a.m. World Boards and Madison River Brewing Company, in partnership with the Friends of the Avalanche Center, sponsors today’s advisory. This advisory does not apply to operating ski areas.
Over the past 24 hours the Bridger Range picked up 15-18 inches of low density snow while the rest of our advisory area picked up 4-6 inches. Winds are currently blowing 20-30 mph out of the WNW with gusts reaching into the 40s at Big Sky and Hyalite. Mountain temperatures are in the single digits to low teens. Today, winds will continue to blow 20-30 out of the WNW and temperatures will warm into the upper 20s F. Snow showers will continue through the morning hours with additional accumulations of 3-5 inches possible by this afternoon. Skies will become partly cloudy by this evening and dry conditions will exist through tomorrow.
The Bridger Range:
Over the past few weeks the Bridger Range has gone from worst to first in terms of snowfall. A favorable northwest flow has provided consistent moisture which has produced respectable snowfall amounts. Over the past 24 hours close to a foot and a half of low density snow has been recorded at the top of the Bridger Lift. This latest round of snow has been accompanied by strong west/northwest winds, which has easily transported the new snow onto leeward slopes.
Today’s primary avalanche concern for the Bridger Range will be any slope that has received a wind load. Although freshly formed wind slabs will be most pronounced along exposed ridgelines, drifts of windblown snow will also be common on the lee side of mid elevation sub-ridges. With more snow and wind forecasted through today, natural avalanches will be likely and human triggered avalanches will be very likely on all wind loaded slopes.
A secondary concern for the Bridger Range will be avalanches failing on faceted layers buried deeper in the pack. Slides initiating within the storm snow and stepping down will be the most likely cause for this type of event. Although the chances of a slide stepping down are becoming less over time, any slide that does step down will likely produce a large and unmanageable avalanche.
Today, the avalanche danger is rated HIGH on all wind loaded slopes and slopes steeper than 35 degrees. Less steep, non wind loaded slopes have a CONSIDERABLE avalanche danger.
The Madison and Gallatin Ranges, the mountains around Cooke City and the Lionhead area near West Yellowstone:
Yesterday I toured into the Lionhead area and was encouraged by the lack of avalanche activity. Although this area received close a foot of snow over the past few days we experienced very few signs of instability. We did receive unstable results during stability tests, but it took hard force to get columns to propagate (video). Snowmobilers in Cabin Creek and Tepee basing in the southern Madison Range got similar results. Doug also found stability to be improving in the mountains around Cooke City on Thursday (photo).
Although buried faceted layers appear to be gaining strength, new snow and strong winds will keep the snowpack on edge. Wind loaded slopes will be today’s primary avalanche concern. Strong winds out of the west/northwest will make slopes on the east half of the compass most prone to wind slab development.
Yesterday, skiers on Mt Wheeler in the northern Gallatin Range experienced widespread cracking and collapsing on wind loaded slopes and a skier in Hyalite got “three scary collapses” on east facing slopes around 8,800 feet. A snowmobiler also triggered a large slide near Buck Ridge this past Wednesday, also on a wind loaded slope (photo).
Although avalanche activity will likely stay confined to the new snow, there is the possibility of avalanches failing on a layer of near surface facets buried 2-3 feet deep. This layer is becoming less active but should not be ignored.
Today, new snow and strong winds will create very dangerous avalanches conditions on wind loaded slopes steeper than 35 degrees which have a HIGH avalanche Danger. All other slopes have a CONSIDERABLE avalanche danger.
Doug 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.
Avalanche Accidents
The accident reports for the avalanche fatality near Cooke City on February 22 and Friday’s avalanche on Saddle Peak are available on our website.
Last Saturday Francis Skierka from Cut Bank, Montana died in an avalanche in northwestern Montana near Marias Pass. Sadly his wife, Andrea, is pregnant and due in two months. A memorial fund to help Andrea and her baby has been established. The Francis Skierka Family Memorial, Stockman Bank, 125 W Main, Cut Bank MT 59427, 406-873-9400
Events/Education
Come to Bridger Bowl on Saturday, March 17th (St. Patrick’s Day) with telemark skis, AT skis, alpine skis, snowboards, split boards, or even snow blades. The theme is Snowpocalypse based on the wildly popular Mayan 2012 apocalypse. $30 gets you into the races, a pint glass, t-shirt, a good time, a raffle ticket, and food by Cafe Fresco. Pre-register at Mystery Ranch or Grizzly Ridge March 11-16. Visit http://pinheadclassic.com/ or the Pinhead Facebook page for more info.