11-12
This avalanche occurred on Saturday, Nov 26. It was triggered by a snowmobiler who was fortunately able to out run the avalanche. This slope was heavily wind loaded and the avalanche broke 3 feet deep. A relatively flat area near the left side of the photograph caused the debris to pile up very deeply. Aspect 160 deg. Elev. 9715. Watch a video of our investigation here:http://www.youtube.com/watch?v=7Z3cgH7eya0 Photo: GNFAC
Forecast link: GNFAC Avalanche Advisory for Mon Nov 28, 2011
This avalanche occurred recently on Fisher Peak near Lulu Pass outside of Cooke City. This slope has a thinner and weaker snowpack than other slopes and also had a heavy load of wind blown snow. Here's our snowpit of the flank: http://www.mtavalanche.com/images/11/fisher-peak?size=_original Photo: GNFAC
Forecast link: GNFAC Avalanche Forecast for Wed Nov 30, 2011
The photo on the right is from a snowmobile triggered avalanche on Crown Butte on 11-26. The photo on the left shows a nearly identical snowpack on nearby Scotch Bonnet Mtn the same day where a stability test broke on facets near the ground (ECTP 17). A similar layer of facets produced the human triggered avalanche on Crown Butte. Slopes with recent avalanches are clear evidence that similar slopes with a similar snowpack structure are prime places to trigger more avalanches. Photo: GNFAC
A deeper snowpack and facets near the ground are producing both natural and human triggered avalanches near Cooke City. This slide occurred on a NE facing slope near Sunset Peak. Photo: Beau Fredlund
GNFAC Avalanche Forecast for Sat Nov 26, 2011
Snowpack and Avalanche Discussion
The old Montana saying, "If you don't like the weather wait five minutes" rang true over the past 24 hours. Yesterday, a fast moving cold front turned a pleasant morning into a raging blizzard within a matter of minutes. By mid-afternoon two to four inches of snow fell in most areas, accompanied by strong-gusty winds.