GNFAC Avalanche Advisory for Fri Jan 20, 2017
Good Morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Friday, January 20th at 6:45 a.m. Today’s advisory is in memory of Tyler Stetson. Tyler was killed in an avalanche in Beehive Basin on this day nine years ago. This advisory does not apply to operating ski areas.
Over the past 24 hours the mountains picked up 1-2” of new snow. This morning, snow has tapered off and skies are partly to mostly cloudy. Temperatures range from the teens to mid-20s F and winds are blowing 5-15 mph out of the W-SW. As the storm system exits to the east, skies will become partly cloudy to mostly clear by this afternoon. Temps will warm into the mid to upper 20s F and winds will remain light to moderate out of the W-SW. The next 24 hour period looks to be dry with seasonal temperatures.
Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
The snowpack has two distinct weak layers capable of producing avalanches. One exists mid-pack and the other near the ground. The lack of snow over the past week combined with warmer temperatures have helped these weak layers gain strength. On Wednesday, Doug got stable results in three different snowpits in the Lionhead area near West Yellowstone (video).
Although buried weak layers are gaining strength, areas of unstable snow still exist. A few natural avalanches earlier in the week are a good reminder that not all slopes are stable (photo, photo, photo, video). Today, use heightened awareness when traveling in steeper terrain, especially areas that have been previously wind loaded. Winds have been relatively calm the past 24 hours, but blew hard earlier in the week out of the W-SW. Areas of wind drifted snow, mainly below upper elevation ridgelines, still have the potential to fail under the weight of a skier or rider.
While the snowpack is trending towards stability, human triggered avalanches remain possible and the avalanche danger is rated MODERATE.
The snowpack in the Bridger Range is mostly stable. On Wednesday, I found an unconsolidated and completely faceted snowpack on the west side (snowpit). The east side (Saddle Peak) yielded a mixed bag of conditions ranging from sastrugi to refrozen chunder (video). Although generally safe avalanche conditions exist, it’s worth watching for unstable snow on isolated terrain features, mainly on previously wind loaded slopes below the ridgelines. Keep in mind that small slides can be dangerous in high consequence terrain.
Today, generally safe avalanche conditions exist and the avalanche danger is rated LOW.
Doug 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 email@example.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.
Advanced Avalanche Workshop w/Field Course, 7-9:30 p.m. Thursday and Friday, January 26 and 27 (MSU Sub Ballroom C); field day, Saturday 28th. Sign up HERE.
Weekly rescue training and snowpack update, 6-7:30 p.m., The Antlers Lodge on Friday, field location Saturday TBA.
January 21, Avalanche Awareness, 6-7:30 p.m., West Yellowstone Holiday Inn.
February 4 and 5, Intro to Avalanches with Field Day, More info and sign up HERE.