Good Morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Advisory issued on Saturday, April 8th at 7:00 a.m. Today’s advisory is sponsored by Grizzly Outfitters in partnership with The Friends of the Avalanche Center. This advisory does not apply to operating ski areas. Bridger Bowl is closed for the season and has backcountry conditions.
At 4 a.m. the mountains have 3-4” of new snow, which began as rain up to 8,000 feet yesterday evening. Temperatures reached the mid-40s F yesterday, and southwest wind was 30-50 mph with gusts of 60-85 mph. Temperatures this morning are mid-20s F to just below freezing with southerly wind at 5-15 mph. Today, temperatures will reach mid-30s F with south wind at 5-15 mph, and tonight wind will shift to the west-northwest at 20-30 mph. Expect light rain and snow in the mountains today with a chance for thunderstorms this afternoon and heavier snow showers tonight. The mountains will get 3-5” of snow by morning with more tomorrow.
Above freezing temperatures yesterday followed by rain and snow create a mix of spring snow conditions today. Before rain and snow fell last night the snowpack was wet and not frozen up to 10,000’ near Bozeman. New snow insulates weak unconsolidated snow where the snowpack did not freeze. The weight of rain and new snow today, or a small loose snow avalanche could trigger a deeper wet avalanche. Natural avalanches are possible with rain or snow today. Avoid steep terrain if the snowpack is wet and not supportable below the new snow, and be cautious of runout zones and steep terrain overhead during precipitation.
Dry loose avalanches are possible in steeper terrain and could propagate wide or run far where a firm crust underlies new snow. Overall, I expect last night’s snow bonded well to a warm snowpack, and light wind today will not form fresh drifts of snow. Yesterday, a skier on the long un-motorized journey into Hyalite saw strong wind knock down trees across the road. Eric was in Beehive and experienced strong winds, but minimal slab formation and an overall stable snowpack. Small drifts of snow are isolated and difficult to trigger today, but are possible and should be avoided or approached with extra caution in high consequence terrain.
Today, the avalanche danger is MODERATE and could rise to CONSIDERABLE if there is heavy rain and snow this afternoon.
As the weather changes daily, so do our avalanche concerns. Check out Doug’s video or my article for more information on spring snow avalanche problems and travel advice.
I will issue our last advisory of the season tomorrow morning by 7:30 a.m.
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!