GNFAC Avalanche Advisory for Sat Nov 28, 2015
Good Morning. This is Eric Knoff with early season snowpack information issued at 7:30 a.m. on Saturday, November 28. Today’s information is sponsored by Montana Ale Works in partnership with the Friends of the Avalanche Center. This information will be updated as conditions change.
High pressure will dominate the weather pattern this weekend and no new snow is expected. This morning a temperature inversion has set up and mountain temps are roughly 10-15 degrees warmer than the valley. At 6 a.m. mountain temperatures range between 10-15 degrees F and winds are blowing 10-20 mph out of the N-NE with stronger gusts being recorded in Hyalite and Big Sky. Today, temps will warm into the mid to upper 20s F under mostly clear skies and winds will continue to blow 5-15 mph out of the N-NE.
Thin snow cover combined with frigid temperatures is not a good recipe for building a strong snowpack. In some areas, the snowpack is completely rotten and faceted, while in others, there’s enough depth and density to ward off the evil effects (for now) that strong temperature gradients produce.
The weakest snow we've identified has been in Beehive Basin (video). The Bridger Range, northern Gallatin Range and mountains around Cooke City seem to be fairing a little better. Yesterday, Alex and I toured near Hyalite Peak and found 75 cm’s of snow above 9,000 ft. The snowpack in this area wasn’t entirely faceted, but it was showing signs of weakening due to the cold temps. Earlier in the week, Doug and Alex found similar snowpack conditions in the Bridger Range north of Bridger Bowl (video, photo).
Farther south, skiers in Cooke City reported finding three feet of dense, strong snow above 9,000 ft. They did not observe any signs of instability such as cracking and collapsing and felt comfortable skiing in avalanche terrain. We have very limited data from the mountains around West Yellowstone, but we will be making a trip there this coming week and reporting back with findings.
Although the snowpack in our area is generally weak, it’s not highly unstable - mostly since we haven't had a recent
EVENTS and AVALANCHE EDUCATION
A complete calendar of classes can be found HERE.
Livingston: December 1, Tuesday, Katabatic Brewing Fundraiser. $1 per pint is being donated to the Friends of the Avalanche Center.
Bozeman: MSU - Introduction to Avalanches with Field Course
December 2, 3 and 5 or 6, 2015: https://www.ticketriver.com/event/16858
Workshops are held on Wednesday and Thursday evenings, with a field course on Saturday. Different topics are presented each evening. Topics include: avalanche terrain recognition, the affect weather has on avalanche hazard, the development of the mountain snowpack, decision making skills, and basic search and rescue procedures.
Butte: December 6, Sunday, Avalanche Awareness for Snowmobilers, Redline Sports, 12-1 p.m.
Billings: December 8, Tuesday, Avalanche Awareness, MSU, 6-7 p.m.
Great Falls: December 9, Wednesday, Avalanche Awareness, Back Alley Pub, 6-7 p.m.
Bozeman: December 9, Wednesday, Avalanche Awareness, REI, 6-7:30 p.m.
Helena: December 10, Thursday, Avalanche Awareness, The Basecamp, 6-7:30 p.m.
West Yellowstone: Snowmobiler Introduction to Avalanches with Field Course
December 17 and 18, 2015: https /www.ticketriver.com/event/17356
Five hours of lectures are followed by a full day field course. Topics include: avalanche terrain recognition, the affect weather has on avalanche hazard, the development of the mountain snowpack, decision making skills, and basic search and rescue procedures.