Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Sunday, March 4 at 7:30 a.m. The Hans Saari Memorial Fund, in partnership with the Friends of the Avalanche Center, sponsors today’s advisory. This advisory does not apply to operating ski areas.
Since yesterday morning southwest Montana picked up another 4-6 inches, although the Hyalite area only got 2-3 inches. This was our fourth day of snow and our second of high winds. West to northwest winds are still averaging 30 mph with gusts in the 50s. Today will continue to be windy and warm with mountain temperatures in the high 20s. High pressure moves in on a northwest flow today bringing mostly sunny skies for the next few days.
The Bridger Range:
Since Wednesday the Bridger Range has gotten over two feet of new snow (about 2” SWE). Two days of strong west winds culminated yesterday with gusts reaching 50 mph at the ridgetops and blowing equally strong from the south at mid-mountain. Forest Service snow rangers could barely stand up in these gusts near Frazier Basin. Expect a moonscape of wind scouring on windward slopes and fat whales of windblown snow on leeward sides. The snowpack in the Bridger Range is faceted and weak at the ground, more so on lower elevation slopes and gullies. Gullies are notorious terrain traps and even small wind drifts on its edges could bury a person.
Traveling in terrain that was benign a few days ago could be quite dangerous today.
Cross-loading from southerly winds will effect both the east and west side of the range. This recipe of strong winds, days of snowfall, and underlying weak snow is reminiscent of the conditions leading up to the Truman Gulch snowboarder fatality last year. Wind-loaded slopes are our greatest concern today and these have a HIGH avalanche danger. Given the steady snow loading over the last four days, all other terrain is rated CONSIDERABLE.
The Madison and Gallatin Ranges, the mountains around Cooke City and the Lionhead area near West Yellowstone:
There are similarities in snow stability in the mountains from Bozeman to Big Sky to West Yellowstone and Cooke City. All these areas received 1-2 feet of snow since Wednesday, all areas received strong west winds and all are showing some signs of instability. Our primary avalanche concern is on steep wind-loaded slopes where it’s very likely to trigger avalanches. Two to three feet under the surface is a thin layer of faceted snow that is breaking in our stability tests. In areas with a thinner snowpack, avalanches can break on facets at the ground. Recent activity includes:
- Reports of collapsing and cracking on slopes in Hyalite and Mt Wheeler in the northern Gallatin Range on Friday.
- Snowmobiler triggered slides on wind-loaded slopes in Buck Ridge in the Madison Range. On Friday an avalanche broke on the thin layer of facets mid pack (photo), and yesterday one broke on the ground (100’ x 100’).
We have spent the last three field days around Lionhead, Cooke City, Cabin Creek and Teepee Basin, and Beehive. Stability tests are showing strengthening (video), but this current round of loading is keeping the snowpack near its breaking point (photo). If folks get into avalanche terrain today I anticipate some will trigger avalanches. Sunny weather can make everything in the backcountry feel better and safer than it really is. Don’t let this influence your decisions; the mountains just got a few feet of new snow along with ripping winds. Today the avalanche danger is HIGH on all wind loaded slopes steeper than 35 degrees. All other terrain is rated CONSIDERABLE.
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.
Avalanche Accidents
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.