Gobble, gobble and Happy Thanksgiving! This is Doug Chabot with early season snowpack information issued at 7:30 a.m. on Thursday, November 26. Today’s information is sponsored by Spark 1 in partnership with the Friends of the Avalanche Center. This information will be updated by Saturday morning.
The big winter storm was a disappointment. Since yesterday morning the mountains only picked up one to two inches with east winds peaking yesterday afternoon at 30-40 mph. At 5 a.m., under clearing skies, temperatures are near 0F with ridgetop winds blowing east at 20-30 mph. Today, temperatures will rise to the low teens under mostly sunny skies and drop to single digits below zero tonight. Friday will be slightly warmer and sunny with east winds continuing.
Storm totals measured 2-4 inches of powder. There was only .2-.3 inches of snow water equivalency, not enough weight to create widespread instability. East winds are an unusual direction and typically mean cold temperatures, no snowfall and wind-loading in unusual areas. Yesterday, in the Bridger Range near Wolverine Bowl, skiers were able to trigger small pockets of windblown snow. In many areas these freshly formed wind slabs are sitting on weak, sugary, faceted snow. This has been noted up Hyalite in the northern Gallatin Range, around Beehive Basin and at Big Sky. Given the similar snow depths further south, I imagine a similar structure can be found in the southern Madison Range and around West Yellowstone. Preliminary reports out of Cooke City indicate these facets may not have developed, but dig to see for yourself.
The mountains have 18 inches to almost three feet of snow on the ground. In some zones the snowpack consists almost entirely of facets like Eric discovered in Beehive Basin (video). Other areas have these facets sandwiched in-between harder layers, which Alex and I found in the Bridger Range (video, photo) and the Big Sky Ski Patrol found during their avalanche control. Cold air temperatures in the next few days will create even more faceted snow in our thin snowpack potentially setting us up for avalanches when the snowfall spigot gets turned on.
Given the new snow, wind and underlying structural weakness, I recommend staying off of wind-loaded terrain where even a tiny pocket avalanching could be injurious. Bundle up, sunscreen your nose and enjoy the start of winter. As always, treat the early season like mid-winter and carry rescue gear and travel with a partner.
Let’s give thanks to our family and friends, those living and passed, during today’s holiday.
Eric will issue a weekend advisory by Saturday morning. We will begin issuing daily advisories and danger ratings once we get a bit more snow. In the meantime, we need your field observations so please drop us a line at mtavalanche@gmail.com.
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.