Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, February 3, at 7:00 AM. Today’s advisory is sponsored by Spark R&D and Community Food Co-op. This advisory does not apply to operating ski areas.
The northwest flow is doing its magic at Bridger Bowl. Yesterday, they got 5 inches of powder so light it did not register on the snow sensors and last night another 13 inches fell. The rest of our area got 1-2 inches from Big Sky to Bozeman and a trace to an inch everywhere else. Winds are westerly and averaging 10-15 mph with gusts of 20-30 mph. Temperatures are in the low single digits F. At 5 a.m. snowfall is tapering as the northwest flow breaks down and a few more inches may be wrung out. Today, most of our area will have partly cloudy skies with temperatures in the mid-20s and 1 to 2 inches falling tonight.
Bridger Range
The new snow is a double-edged sword. On the positive, it is such low density that even 18 inches has hardly registered on the scales that measure snow water weight (.2” SWE). I’m guessing 1-3% cold smoke powder. On the negative side, it is blowing a steady 30 mph from the west creating thick wind slabs that can be easily triggered. Even without wind-loading, loose snow avalanches will be common.
Eric and I tag-teamed the Bridger Range yesterday with him on the west side of the ridge and myself further north at the Throne. Overall we found a strengthening snowpack, but the variability in our snowpits makes stability assessment more complicated. It is easy to dig, find strong and stable snow and assume it is everywhere, when it is not. We each made a video to explain how to navigate this problem and it is worth watching both of them (Doug’s video, Eric’s video).
Fresh slabs of new snow and windblown snow along with loose avalanches are enough to keep us on your toes. Avalanches are most likely to occur during and immediately after a storm, and today the avalanche danger is rated HIGH on all wind-loaded slopes and CONSIDERABLE on all others.
Madison Range Gallatin Range Lionhead area near West Yellowstone Cooke City
As the snowpack gets stronger I am becoming less nervous, but still wary. As mentioned above, variability is increasing and can lead to a false sense of security. Our messaging in yesterday’s two videos applies to our entire forecast area. Depth hoar at the ground is found on all slopes while a layer of small facets buried two feet under the surface is found on some. These two weak layers are not very reactive and the likelihood of triggering them is decreasing, but not uniformly. People are triggering avalanches, albeit smaller, but still dangerous. For example, on Monday a sledder triggered a slide in Lionhead as he traversed a steep wind-loaded slope (photo) and a skier popped a small slide near Cooke City too (photo). For today, triggering avalanches is still possible and the danger is rated MODERATE.
Darren Johnson Avalanche Education Memorial Fund
The National Avalanche Foundation set up an education fund in memory of Darren Johnson, the Yellowstone Club ski patroller who died in an avalanche on January 19. You can check out the details and make donations here: http://www.mtavalanche.com/sites/default/files/NAF%20Darren%20Johnson%20Memorial%20Fund.pdf.
Alex will issue the next advisory tomorrow morning by 7:30 a.m. If you have any snowpack or avalanche observations to share, drop us a line at mtavalanche@gmail.com or leave a message at 587-6984.
EVENTS and AVALANCHE EDUCATION
A complete calendar of classes can be found HERE.
TONIGHT, Bozeman, Wednesday, February 3: 1hr Avalanche Awareness, Best Western Grand Tree Inn, 7:30-9:00 p.m.
West Yellowstone, Saturday, February 6: 1hr Avalanche Awareness, West Yellowstone Holiday Inn, 7-8 p.m.
Bozeman, Tuesday, February 9: 1hr Avalanche Awareness for Snowmobilers, Summit Motorsports, 6-7 p.m.
SATURDAY at BRIDGER BOWL: February 6, King and Queen of the Ridge. A day of hiking and skiing the Ridge as a fundraiser for the Friends of the Avalanche Center. Teams and individuals are welcome! More info here: http://bridgerbowl.com/event/king-and-queen-of-the-ridge.