Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, January 3rd at 7:15 a.m. Today’s advisory is sponsored by Bountiful Table and Edward Jones. This advisory does not apply to operating ski areas.
A trace to 1” of snow fell in the last 24 hours with light winds. This morning, under partly cloudy skies, thermometers are showing -15F in the northern mountains with 5 to 10 degrees warmer at the ridgetops from an inversion. The southern mountains are -5F. Today will warm to near zero before chilling back to minus teens tonight with light winds and mostly clear skies. The arctic air is expected to last through Thursday followed by a high-pressure ridge of seasonable temperatures for the weekend.
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
Every time it snows we get naturally occurring avalanches, the number one sign of instability. Right now, without much snow or wind-loading, avalanches are becoming rare and we rely on stability tests and red flags of cracking and collapsing to help determine stability. Yesterday in the Bridger Range two separate parties, one in on the west side in Bostwick Canyon and another on the east side in the Throne area, reported cracking and “whumphing” of the snowpack on wind-loaded slopes (photo). This instability is not widespread, but feeling just one whump is a warning to avoid avalanche terrain.
A layer of weak sugary snow undermines the snowpack. Digging to the ground reveals a foundation of low-density crumbly snow (depth hoar) supporting 3-7 feet of denser snow. This structure is untenable and was responsible for a natural avalanche on Sunday in the northern Gallatin Range in Storm Castle Creek on a steep wind-loaded slope as well as an avalanche cycle outside Cooke City last week. Without snowfall and strong wind in the last 36 hours this layer is getting a breather from loading. The likelihood of triggering an avalanche is decreasing, yet still possible. I was in Cooke City over the weekend and found that impacting the weak layer near the ground is getting difficult except in thinner areas where a rider or skier could still trigger a slide (video). For today, the avalanche danger is rated MODERATE on all slopes throughout our advisory area.
In the last 7 days we have visited Cooke City, Saddle Peak, Taylor Fork and Hebgen Lake. Check out our YouTube playlist for videos from each of these areas, our website with many photos of the recent avalanche activity and our snowpit profile page to get a handle on the snow structure.
I will issue the next advisory tomorrow morning by 7:30 a.m.
We rely on your field observations. Send us an email with simple weather and snowpack information along the lines of what you might share with your friends: How much new snow? Was the skiing/riding any good? Did you see any avalanches or signs of instability? Was snow blowing at the ridgelines? If you have snowpit or test data we'll take that too, but this core info is super helpful! Email us at mtavalanche@gmail.com or leave a message at 406-587-6984.
Month of January: Montana Ale Works has chosen the Friends of the Avalanche Center as January's "Round It Up America" recipient. Every time you round-up your bill the change gets donated to the Friends. Pennies equal dollars!
BOZEMAN
TOMORROW, Wednesday, January 4, Avalanche Awareness, 6-7:30 p.m. @ REI
Tuesday, January 10, Women’s Avalanche Awareness and Beacon Practice, 6-8 p.m., Beall Park
Friday and Saturday, January 13 and 14, Companion Rescue Clinic, REI Friday 6 p.m., field Saturday TBA. Register here: https://events.ticketprinting.com/event/21313
Tuesday, January 17, Avalanche Center Forecaster’s Social at Montana Ale Works. A small-plate fare and beer tasting fundraiser for the Friends: $40.00/person; 2 seatings (5:30 p.m. and 7:00 p.m). Get your tickets HERE.
COOKE CITY
Weekly rescue training and snowpack update, 6-7:30 p.m., The Antlers Lodge on Friday, field location Saturday TBA.
GREAT FALLS
Friday, January 6, Avalanche Awareness, 6-7:30 p.m., Hi-Line Climbing Center
WEST YELLOWSTONE
Saturday, January 7, Avalanche Awareness, 7-8 p.m., Holiday Inn West Yellowstone
DILLON
Tuesday, January 10, Avalanche Awareness, 6-7:30 p.m., UM-Western Library