Good Morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Thursday, January 26th at 7:00 a.m. Today’s advisory is sponsored by Gallatin County Search and Rescue and Spark R&D. This advisory does not apply to operating ski areas.
Overnight a sneaky snowstorm entered the Bridgers and dropped 6-8” of low density snow. This puts the 24 hour total at Bridger Bowl close to a foot. The rest of the advisory area picked a trace to 1”. At 5 a.m. it’s still snowing at Bridger Bowl and skies are partly to mostly cloudy elsewhere. Temperatures are in single digits above zero F with the exception of Cooke City where temps are a few degrees below zero F. Winds are blowing 5-15 mph out of the W-NW. Snow showers will linger in the northern mountains this morning, but the storm pushes out by this afternoon and skies will become partly to mostly cloudy. A ridge of high pressure builds over the area tonight and tomorrow producing clear and calm conditions.
Bridger Range
The Bridger Range finally got a well needed snowstorm. Close to a foot of low density snow over the past 24 hours will be enough to increase the avalanche danger. Although Bracket Creek Snotel site is only showing .3” of SWE, I’m guessing totals are higher near the ridgeline. The snowpack in the Bridger Range is very weak and will struggle to support the new load. Today, loose snow and soft slab avalanches will be likely on steeper slopes.
For this reason, the avalanche danger is rated CONSIDERABLE in the Bridger Range.
Madison Range Southern Gallatin Range
Lionhead area near West Yellowstone Cooke City
Depth hoar near the ground remains the weakest layer in the snowpack. On many slopes, this layer has gained strength and is unlikely to produce avalanches (video). On other slopes it remains weak and less capable of supporting the overlying snow. On Wednesday, Doug and his partner found an unstable slope on an east aspect up Lightning Creek in the Southern Madison Range (video, photo, snowpit profile). They backed off their objective and skied lower angle terrain back to the sleds.
The tricky part about current conditions is many slopes are stable but a few are not. Figuring out which slopes are stable and which slopes are not requires digging a snowpit and doing a quick stability test. It’s not worth throwing caution to the wind and assuming that all steep slopes are stable and safe.
In addition to buried depth hoar, isolated wind slabs are also a concern. This problem exists in upper elevation, alpine terrain. Watch for and avoid areas of wind drifted snow, especially in steep high consequence terrain.
Today, natural avalanches are unlikely, but human triggered avalanches are possible and the avalanche danger is rated MODERATE.
Northern Gallatin Range
The northern Gallatin Range has good stability. There may be a few lingering wind slabs near the ridgelines, but these will be small and easy to avoid. Other than isolated areas of wind drifted snow, the snowpack is mostly stable.
For this reason, human triggered avalanches are unlikely and the avalanche danger is rated LOW.
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!
King and Queen of the Ridge, Saturday, February 4th. A Hike and Ski/Ride-a-Thon fundraising event to support the Friends of the Gallatin National Forest Avalanche Center. Register with Bridger Bowl HERE, make pledges HERE.
Beacon Training Park at Beall: Open and free to the public for avalanche beacon practice seven days a week from 9 a.m. to 8 p.m., southeast corner of Beall Park in Bozeman.
COOKE CITY
Weekly rescue training and snowpack update, 6-7:30 p.m., The Antlers Lodge on Friday, field location Saturday TBA.
DILLON
February 4 and 5, Intro to Avalanches with Field Day, More info and sign up HERE.