09-10
GNFAC Avalanche Forecast for Sat Jan 30, 2010
Snowpack and Avalanche Discussion
The Madison Range, southern Gallatin Range and the Lionhead area near West Yellowstone:
A snowmobiler triggered this avalanche in the Bridger Range north of Ross Peak on Wednesday 1-28. A shallow snowpack and buried facets a foot off the ground continue to make avalanches possible in the Bridger Range. Photo by GNFAC
Forecast link: GNFAC Avalanche Forecast for Sat Jan 30, 2010
GNFAC Avalanche Advisory for Fri Jan 29, 2010
Snowpack and Avalanche Discussion
The Madison Range, southern Gallatin Range and the Lionhead area
near West Yellowstone:
From an email, "...It occurered in Sunlight Basin toward the west end of the bowl. This one released as soon as I made my turnout at the top, so I rode down in the motion of the slide. As seen in the photo, this is a north facing slope, ~40 degrees, 12" crown, ran for 100' downhill, and was 100' wide. The crown showed that basically all of the new snow we have recieved this past week let loose from the hill.
Forecast link: GNFAC Avalanche Advisory for Tue Feb 2, 2010
This avalanche was triggered on Jan 28 as a snowmobiler approached a small slope and shows the sensitivity of buried facets near Big Sky. Photo: S. Reznicek
Forecast link: GNFAC Avalanche Advisory for Fri Jan 29, 2010
GNFAC Avalanche Forecast for Thu Jan 28, 2010
Snowpack and Avalanche Discussion
The Madison Range, southern Gallatin Range and the Lionhead area near West Yellowstone:
Yesterday an observer in the southern Madison Range reported a large skier triggered avalanche that broke 8 inch diameter trees and was big enough to bury a car. It fractured over most of the avalanche path on facets near the ground and occurred on an east aspect at an elevation of 7600 ft. The scariest thing about this avalanche is that it was triggered from a 30 degree slope and propagated a fracture uphill to a 35 degree slope.
This layer of buried surface hoar is a problem in the southern Madison Range. Its not widespread and seems to be absent on south facing slopes and high alpine slopes, but I found it on many others. As I skinned on the flats my partner and I got a huge "whumph" and I could see a crack 200 feet away on a small hill. It fractured on this layer and answered the question, "Can this layer propagate a fracture?" with a resounding YES. Photo: Doug Chabot
GNFAC Avalanche Forecast for Wed Jan 27, 2010
Snowpack and Avalanche Discussion
The Madison Range, southern Gallatin Range and the Lionhead area near West Yellowstone:
GNFAC Avalanche Advisory for Tue Jan 26, 2010
Snowpack and Avalanche Discussion
The Madison Range, southern Gallatin Range and the Lionhead area near West Yellowstone: