Wet loose avalanches on sun exposed slopes were seen up Hyalite early Tuesday afternoon. Photo: H. Coppolillo
Forecast link: GNFAC Avalanche Advisory for Wed Mar 14, 2018
Forecast link: GNFAC Avalanche Advisory for Wed Mar 14, 2018
17-18
Forecast link: GNFAC Avalanche Advisory for Wed Mar 14, 2018
GNFAC Avalanche Forecast for Tue Mar 13, 2018
Snowpack and Avalanche Discussion
<p>Today’s avalanche concerns center on sunny, calm and warm weather. The surface snow will get no cooling effect from a breeze nor will the snow be shielded from the sun by clouds. It’s a warm day and no mountain range is immune to loose, wet snow avalanches on sunny, mostly south-facing, slopes (<strong><a href="https://www.mtavalanche.com/images/18/wet-loose-avalanches">photo</a></…;). The danger from today’s wet avalanches do not lie in triggering them below your feet, but in having one hit you from above and carry you down a slope. Above freezing temperatures also make cornices weak. These overhangs of snow already teeter and melting will only make them more likely to break. A passing skier triggered a large cornice in the Hourglass Chute north of Bridger Bowl on Saturday (<strong><a href="https://www.mtavalanche.com/images/18/cornice-triggered-hourglass-chute…;), and with today’s temperatures cornices will break even easier.</p>
<p>Underneath the surface the snowpack is dry, strong, and lacks widespread weak layers. Cooke City experienced wind slab avalanches over the weekend (<strong><a href="https://www.mtavalanche.com/images/18/natural-wind-slab-near-cooke">pho…;, <a href="https://www.mtavalanche.com/images/18/skier-triggered-wind-slab-near-co…;) that possibly failed on a layer of ball-bearing graupel (<strong><a href="https://www.mtavalanche.com/images/18/graupel-layer-cooke">photo</a></s…;), but this instability will heal quickly. Our snowpits and other field observations reveal stable conditions in our advisory area (<strong><a href="https://youtu.be/0jpDHOgb7Hs">video</a></strong>). Today, the <strong><u>dry snow avalanche danger</u></strong> is rated <strong>LOW</strong> on all slopes. A low danger means avalanches are unlikely, but not impossible.</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
LIVINGSTON
March 20, Beer for a Cause Night at Katabatic Brewing, 4-8p.m. A dollar from every pint will be donated to The Friends of the Avalanche Center.
Wet loose avalanches can be seen in lower elevation gullies on southwest facing slopes of Sphinx Mountain. Photo: B. VandenBos
Forecast link: GNFAC Avalanche Forecast for Tue Mar 13, 2018
Weather and Avalanche Log for Tue Mar 13, 2018
Temperatures reached upper 40s F in afternoon.
Roller balls are a sign that the surface snow is getting moist. As these become more numerous and grow in size, they indicate that the surface snow is getting wet enough to create shallow, loose snow avalanches. Photo: H. Coppolillo
Forecast link: GNFAC Avalanche Forecast for Tue Mar 13, 2018
This layer of graupel, small ball-bearing pellets, is 30-60 cm under the surface in Cooke City and was responsible for some avalanches over the weekend. Graupel bonds quickly because of it's round shape and this instability will not last long. Photo: J. Schutz
A rider noted multiple natural avalanches around Cooke City over the weekend (3/10-3/11). Photo: J. Schutz
A cornice fall triggered this large avalanche over the weekend (3/10-3/11). Cornices are massive and can break naturally and trigger large slides on slopes below. Give them extra distance along ridgelines and avoid traveling below them. Photo: J. Schutz