Good Morning. This is Alex Marienthal with the 138th and last daily avalanche advisory of the season issued on Sunday, April 9th at 7:00 a.m. Today’s advisory is dedicated to everyone who supported our operation by reading the advisories; taking an avalanche class; donating money, time or gear; or sending in a backcountry observation. Our success is directly related to community support and the Forest Service. Thank you for 27 great seasons. This advisory does not apply to operating ski areas. Bridger Bowl is closed for the season and has backcountry conditions.
At 6 a.m. the mountains have 4-6” of new snow. Temperatures are high teens to 20s F and wind is west-northwest at 5-20 mph. Today, temperatures will be 20s to low 30s F with west to northwest wind at 15-25 mph. The mountains will get 1-2” of snow this morning before dry weather prevails tonight through tomorrow. More mild and unsettled weather is in the forecast later this week.
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
Today’s new snow makes dry and wet loose avalanches possible in steep terrain. These slides can run long distances and become large where a firm crust lies below the new snow. In areas that got more snow, dense slabs of new snow are possible for a skier or rider to trigger.
Fresh drifts of snow from moderate west to northwest wind are easy to trigger today. These wind slabs are found near ridgelines and below cliffs, and could be 1-2 feet thick. Approach freshly wind loaded slopes with caution, or avoid them altogether today. Cornices are huge right now and can be triggered from farther away than expected. We had a couple reports this season from skiers that fell into cracks on ridgelines behind cornices. Give cornices a lot of space on the ridgeline above and minimize exposure to slopes below.
Today, new snow creates the avalanche hazard and avalanches deeper than the new snow are unlikely. New snow stability can quickly change on a spring day, and decrease with above freezing temperatures or brief sunshine. New snow may bond well to the old snow on the first run of the day, then easily slide on the second. Last night’s snow fell on a range of surfaces, from dry snow on shady north aspects to wet snow and crusts on warm, sunny slopes. Expect stability to change as you travel to different aspects and elevations. Anticipate and observe changes and be ready to change plans or move to safer terrain, ideally before stability gets worse.
Today, new snow and wind make the avalanche danger CONSIDERABLE on wind loaded slopes and MODERATE on non-wind loaded slopes.
After a forecast for rain and snow yesterday, I was surprised to be in a t-shirt while touring under blue skies at Bridger. In other mountain ranges temperatures stayed cooler under cloudy skies and snow stayed drier. A variety of conditions during spring create a mix of avalanche problems that can arise relatively quickly. See our recent videos (Doug’s, Alex’s) or my article for more information on spring snow avalanche problems and travel advice.
If conditions warrant we will issue intermittent avalanche information. If you have any snowpack or avalanche observations drop us a line at mtavalanche@gmail.com or call us at 587-6984
Water Supply Outlook Report
NRCS just released their monthly water report. On March 31 the Gallatin River Basin was 87% of average, the Madison was 104% and the upper Yellowstone was 117%. You can download the full report HERE.
MAY 4: Give Big Gallatin Valley
The Friends of the Avalanche Center are one of the recipients of the Give Big Gallatin Valley campaign. It is a 1-day fundraising event for local non-profits on May 4, so mark your calendars. The Friends will send reminders as the day approaches: https://www.givebiggv.org/organizations/friends-of-the-gallatin-national-forest-avalanche-center
MAY 20: SPRING SLED FEST in Cooke City
A fundraiser for the Friends of the Avalanche Center. $20 raffle tickets for sweet prizes; free BBQ on the mountain; raffle and party at Soda Butte Lodge 8 p.m. Check out the poster!