20-21

<p>The Avalanche Warning in the southern Madison, southern Gallatin and Lionhead areas has expired. These mountains have a weak snowpack with its bottom third composed of unstable sugary facets. This structure is unsupportable making it easy to poke a ski pole to the ground or dig your track to the dirt. Yesterday, this area got 9” of snow with .8” of <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2… water equivalent</u></a> (SWE) which spiked the danger. Avalanches were seen on Lionhead Ridge. Before the storm, widespread whumpfing and collapses were felt throughout all three ranges. Dave forewarned us of the increasing danger in his <a href="https://www.youtube.com/watch?v=KLSgnetPsDg"><strong><u>video on Monday</u></strong></a>. This was the area’s largest storm since mid-November and today the snowpack will still be adjusting to the added weight of the new snow. Avoid getting on or underneath avalanche terrain because triggering slides is likely today and the danger is rated CONSIDERABLE.</p>

<p>The Avalanche Warning for the Bridger Range has expired. Yesterday morning’s 9” of snow with .8” SWE fell with strong wind. Avalanches occurred during the storm and wind continues to load slopes. Saddle Peak avalanched for the second time in 5 days, and the adjacent slope, Argentina Bowl, also slid (details: <a href="https://www.mtavalanche.com/node/23556"><strong><u>Saddle</u></strong><…;, <a href="https://www.mtavalanche.com/node/23567"><strong><u>Argentina</u></stron…;). Avalanches released a couple feet deep on sugary facets that underlie most slopes in the range. Ian and I went to the Fairy Lake/Frazier Basin area and watched slopes get stripped by gale winds on one aspect and loaded onto another (<a href="https://youtu.be/RYLiP2EjcC8"><strong><u>video</u></strong></a&gt;). They were loading at the ridgetop from the west, and southerly at mid-mountain. Today, these newly formed wind drifts should be avoided as they will easily crack and avalanche. For today the avalanche danger is rated CONSIDERABLE on all wind-loaded slopes and MODERATE on all others.</p>

<p>The snowpack in the northern Madison and northern Gallatin Ranges struggled to hold yesterday’s storm snow (9” near Big Sky, 4-6” in Hyalite). Yesterday, a natural avalanche on Fan Mountain (<a href="https://www.mtavalanche.com/images/21/natural-avalanches-fan-mountain">…;) near Big Sky and a sizable crack and collapse in Lick Creek in Hyalite (<a href="https://www.mtavalanche.com/images/21/collapse-and-crack-lick-creek"><s…;) illustrate the weakness of the snowpack. A thick layer of faceted, sugary snow near the ground was under strain from the weight of the new snow. The layer is still weak, but without active loading the chances of triggering a slide has lessened. No matter, it is still prudent to be conservative, especially on wind-loaded slopes, where triggering slides is still possible. For today, the avalanche danger is MODERATE on all slopes.</p>

<p>The mountains around Cooke City lack widespread weak layers, however, avalanches are still possible. This means just you’ll have to dig and test the snow and travel with your senses keen to whumpfs and collapses, a sign of unstable snow underfoot. Yesterday, a natural avalanche on Mineral Mountain (<a href="https://www.mtavalanche.com/node/23577"><strong><u>details</u></strong>…;), a skier-triggered slide on Henderson Mountain (<a href="https://www.mtavalanche.com/node/23573"><strong><u>details</u></strong>…;), as well as red flags of collapses and cracks are evidence of isolated weakness and lurking instability. For today, the avalanche dangerous rated MODERATE.&nbsp;</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>