Good Morning. This is Eric Knoff with early season snowpack information issued at 10 a.m. on Friday, November 20th. Today’s information is sponsored by Gallatin County Search and Rescue in partnership with the Friends of the Avalanche Center. This information will be updated as weather and snow conditions change.
Over the past 24 hours the northern Gallatin Range (Hyalite area) received 10 inches of low density snow totaling .5 inches of SWE. The mountains around Big Sky, West Yellowstone and Cooke City picked up between 5-7 inches, while the Bridger Range squeezed out about 4 inches. This morning, temperatures range from the single digits to low teens F and winds are blowing 15-25 mph out of the W-NW. Today, scattered snow showers will continue in the mountains with additional 1-2 inches possible. Temperatures will slowly warm into the low to upper teens F and winds will continue to blow 15-25 out of the W-NW. By this evening snow showers will taper off and skies will become mostly clear. Temperatures will be cold tonight dropping into the single digits, but Saturday will provide plenty of sunshine and temperatures in the 20s F.
Montana is notorious for wild weather and the past few days have been no exception. Prior to onset of this latest snowstorm, southwest Montana experienced one of the worst wind storms it has seen in years. On Wednesday, Timber weather station at the Yellowstone Club recorded a wind gust of 92 mph while gusts between 75-85 mph were recorded elsewhere. This violent wind storm downed hundreds of trees at Bridger Bowl, Big Sky and the Yellowstone club, and there’s no question the forests in the surrounding backcountry suffered extensive damage as well. Outside of the avalanche hazard, downed trees are certainly something to look out for.
Although this latest snow storm wasn’t quite as strong as the recent wind storm, it still produced some descent snow totals. As mentioned above, the northern Gallatin Range topped the charts with 10 inches of new snow while the rest of the advisory area picked up between 4-7 inches. This new snow is light and fluffy and will easily be transported by moderate winds out of the W-NW. This provides the perfect recipe for wind slabs, which will be today’s primary avalanche concern.
Fresh wind slabs will be most widespread on upper elevation slopes facing the east half of the compass, but it’s worth evaluating every aspect before dropping in. On some slopes, wind deposited snow will be sitting over weak faceted snow near the ground (photo, photo, video), which will make these slopes the most unstable. However, every slope with wind deposited snow should be evaluated carefully before hiking up or skiing down. Signs of instability such as cracking and collapsing or recent avalanche activity are obvious clues the slope is unstable. It will be best to avoid areas where these signs are present. If you are heading into the backcountry over the next few days, pay close attention to changing snow conditions and always be assessing the terrain above and below you. It’s important to remember that avalanches can be triggered on the hike up or from a distance and even small slides can have severe consequences.
We will begin issuing danger ratings when there is more snowfall. Meanwhile, we will update this information as conditions change. We need your observations, so please drop us a line at mtavalanche@gmail.com if you get out.
mtavalanche.com Website
We are making a few changes to our weather page. Although most of the stations are up and running, it’ll be a week before we get things posted in a new graphical and numerical format.
AVALANCHE EDUCATION
A complete calendar of classes can be found HERE.
Rescue Volunteers Needed
Gallatin County Search and Rescue's Winter Backcountry Hasty team is having an orientation for new and established members on November 23rd (1830hrs) at the SAR building at the SE corner of the fairgrounds. This group responds to winter backcountry SAR events and requires excellent winter backcountry and avalanche skills. If you would like to join, please contact Scott at helialpha@gmail.com
MSU - Introduction to Avalanches with Field Course
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.
December 2, 3 and 5 or 6, 2015: https://www.ticketriver.com/event/16858
West Yellowstone: Snowmobiler Introduction to Avalanches with Field Course
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.
December 17 and 18, 2015: https /www.ticketriver.com/event/17356