17-18
A screenshot of Get Avalanche Smart - Growing Up, the first of 4 short films promoting avalanche education that were produced by the Friends of the Avalanche Center. https://youtu.be/MtFmJYhWG58
Weather and Avalanche Log for Tue Nov 7, 2017
single digits F overnight
This slab avalanche was observed in Republic Creek on Monday, November 6. It's on a NE aspect, around 9,800' and estimated to be about 5' deep and 50' wide. Photo: B. Fredlund
GNFAC Avalanche Advisory for Mon Nov 6, 2017
Snowpack and Avalanche Discussion
<p>It sure looks like winter out there! There’s 2-4 feet of snow in the mountains and people have been getting out skiing, including us. Reports from Cooke City, Hyalite and the Bridger Range are surprisingly similar: on slopes that have not been wind-loaded the stability is mostly good. The snow structure is mostly “right-side up” which means less dense, powdery snow is sitting atop denser, supportable snow. These snowpits graphically show this stable structure (<strong><a href="https://www.mtavalanche.com/images/17/west-woody-ridge">snowpit1</a></s…;, <strong><a href="https://www.mtavalanche.com/images/17/bridger-pit-profile-3-nov">snowpi…;).</p>
<p>Wind-loaded slopes are not stable. Evidence of this instability are recent avalanches near Fairy Lake (<strong><a href="https://www.mtavalanche.com/images/17/natural-avalanche-near-fairy-lake…;), Saddle Peak (<strong><a href="https://www.mtavalanche.com/images/17/saddle-peak-slide-5-november-17">…;) and Hyalite Peak. Even though wind speeds have not been strong, speeds of 15 mph are more than enough to blow and drift snow into unstable wind slabs.</p>
<p>Alex, Eric and I have been in the Bridger and northern Gallatin Ranges the last three days and are in agreement that slopes untouched by the wind are generally stable, but those near the ridgetops are suspect (<strong><a href="https://youtu.be/fcRlhZKUlBQ">video</a></strong>). Wind will be the primary factor creating unstable conditions in the coming days.</p>
<p>We will begin issuing daily avalanche advisories and danger ratings when the mountains get more snow. Our field data is currently limited. Besides our own field days we rely on others to help us form a picture of what’s happening across our forecast area. If you get out and have any avalanche or snowpack observations to share, drop a line via our <a href="https://www.mtavalanche.com/node/add/snow_observation">website</a>, email (<a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a>), phone (406-587-6984), or Instagram (#gnfacobs).</p>
Get Avalanche Smart – Growing Up
The Friends of the Avalanche Center present the first of 4 short films promoting avalanche education. Ben Goertzen explains why it is important to take an avalanche class. VIDEO.
Upcoming Avalanche Education and Events
BILLINGS
7 November, Avalanche Awareness, 6-7:30 p.m. at Basecamp, Billings
BUTTE
Forecast link: GNFAC Avalanche Advisory for Mon Nov 6, 2017
This slide on Saddle Peak occurred during or shortly after the storm on Nov. 3rd-4th. The slope appears to be wind loaded and the slide was likely triggered by a cornice fall. Photo: GNFAC
Forecast link: GNFAC Avalanche Advisory for Mon Nov 6, 2017
Two skiers took this picture skinning up the Fairy Lake Road in the Bridger Range. Wind had been moving lots of snow around; pretty active loading on ridge tops as well as lower elevation spots. The lower hills surrounding the approach to Ainger Basin from the road were heavily loaded as well. Photo: G. Antonioli
Forecast link: GNFAC Avalanche Advisory for Mon Nov 6, 2017