17-18
We were finding 4 feet of snow on E and S facing slopes and 6 feet on north facing. All pits showed stability and we only saw one small cornice triggered slide all day. In this pit Eric found a few ice crusts (south facing slope), but no breaks in tests. We had no other signs of instability and we skied the slope. Photo: GNFAC
GNFAC Avalanche Forecast for Mon Nov 20, 2017
<p>My primary avalanche concern for the next couple days is fresh wind slabs cracking and avalanching. Skiers in the Bridger Range, up Hyalite, near Big Sky and on Ramshorn Peak in the southern Gallatin all reported winds blowing snow over the weekend (<strong><a href="https://www.mtavalanche.com/images/17/gusty-winds-hyalite">photo</a></s…;). A few wind slabs cracked as skiers slid by. Winds became strong and gusty last night further thickening wind slabs and increasing their chance of being triggered.</p>
<p>In all our ranges, except Cooke City, there are a few slopes with weaker, faceted snow near the ground. Snowpacks thinner than 3’ deep at higher elevations are where this layer is prominent. Eric found it in Beehive Basin on Saturday, and although he could not get this layer to break in his stability test, he is still cautious. His <strong><a href="https://youtu.be/u2sRTMjaIcI">video</a></strong>, titled “Could be Worse”, explains his concern and optimism. Yesterday at Big Sky Ski Area the patrol was able to trigger avalanches with explosives at the ground on heavily wind-loaded slopes (<strong><a href="https://www.mtavalanche.com/images/17/big-sky-avalanche-control">photo<…;). We pay close attention to early season avalanche control at ski areas since their snowpack resembles the backcountry. The avalanches at Big Sky are warnings that some slopes have weak, unstable snow.</p>
<p>Outside Cooke City there is a 4-5’ deep snowpack that is mostly stable (<strong><a href="https://www.mtavalanche.com/images/17/mt-republic-profile">snowpit profile</a></strong>) with the exception being wind-loaded slopes. These mountains have lots of snow and recent wind. Wind-loaded slopes are the most dangerous and on Friday snowmobilers saw a natural avalanche cover their tracks on Mt. Abundance (<strong><a href="https://www.mtavalanche.com/images/17/debis-natural-avalanche-mt-abunda…;).</p>
<p>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>
Upcoming Avalanche Education and Events
BOZEMAN
Nov. 28, Avalanche Awareness, 6-7:30 p.m. at Play it Again Sports
Nov. 29, 30 and Dec. 2, 3 or 9, Introduction to Avalanches w/ Field Day, Info and Register Here
Dec. 6, Avalanche Awareness, 6-7:30 p.m. at REI Bozeman
Weather and Avalanche Log for Mon Nov 20, 2017
Temps: mid 20's in N; high teens in S
High elevation slopes that were heavily wind-loaded (N-E) avalanched with explosives during control work. Crowns were near 3 feet deep and the slides broke at the ground. Photo: BSSP
Gusty, intermittent winds from the SW blew in Hyalite yesterday and formed windslabs of variable thickness. These small, stiff, slabs were reactive to ski cuts. Photo: G. Antonioli
Forecast link: GNFAC Avalanche Forecast for Mon Nov 20, 2017