Good Morning. This is Ian Hoyer with the Gallatin National Forest Avalanche Forecast on Saturday, February 27th at 7:30 a.m. Today's forecast is sponsored by Summit Motorsports and Ski-Doo and Grizzly Outfitters. This forecast does not apply to operating ski areas.
In the last 24 hours, it snowed 10” near West Yellowstone, 7” in the Bridger Range, and 3-4” across the rest of the advisory area. Winds are westerly at 10-15 mph with gusts of 25 mph. Moderate westerly winds will continue today. Temperatures are in the single digits and teens F this morning and will rise into the teens F this afternoon. Light snowfall today won’t bring much accumulation.
The fresh snow is piling up and human triggered avalanches are likely today in the Lionhead area. With more than a foot of new snow over the last two days, avalanches can break either under the new snow, or step down to weak layers at the bottom of the snowpack. Avalanches in the new snow will be most easily triggered and the largest on slopes where it has been drifted into deeper cohesive slabs. The weak layers at the ground are unlikely to give you any warning before you trigger an avalanche. Give them time to accommodate this load of new snow. Avoid riding on or underneath all steep slopes. The avalanche danger is rated CONSIDERABLE.
With a little less new snow, avalanches aren’t quite as likely across the rest of the advisory area, but triggering one is possible and they could break very deeply. Strong winds over the last few days created wind drifts that will be harder to identify with a dusting of new snow on top. Winds dropped off last night, so on many slopes the most recent snow won’t be drifted but particularly watch out if you find one where it was. These drifts can avalanche under the weight of a skier or rider. Yesterday, riders on Buck Ridge saw a recent avalanche that broke naturally on a wind-loaded slope (photo).
The more serious issue is that we have the recipe for deep slab avalanches. Deep slabs are tricky. It’s hard (maybe impossible) to figure out which particular slope is going to break, but if a slope goes, the resulting slide will be huge and deadly (Blackmore video, McAtee Basin video). We don’t trust the snowpack and neither should you. Continuing to avoid all steep slopes is the best solution.
With large human triggered avalanche possible, the avalanche danger is rated MODERATE.
Avalanches beneath recently wind-drifted snow remain the primary concern near Cooke City, but avalanches breaking deeper are also possible. Earlier this week, an avalanche broke deeply on weak layers near the ground on a wind-loaded slope in Hayden Creek (details). This slope had avalanched several times already this year keeping the snowpack unusually thin and weak. While these conditions aren’t widespread, stay on alert in case you encounter one of these thin areas with weaker snow. The avalanche danger is rated MODERATE today.
The Beacon Park at Beall Park in Bozeman is running!
The Friends of the Avalanche Center in partnership with the City of Bozeman put in a Beacon Park at Beall Park. It is located on the north side of the Beall building between N. Bozeman Ave. and the ice rink. Stop by with your avalanche transceiver and do a few practice rescue drills. Your partner will thank you.
Upcoming Avalanche Education and Events
See our education calendar for an up-to-date list of all local classes. Here are a few select upcoming events and opportunities to check out:
Every Saturday in Cooke City, FREE snowpack update and rescue practice at the Round Lake Warming Hut between 10 a.m. and 3 p.m. Poster with More Info.
The video recording of Dave’s recent talk on “Rethinking Avalanche Terrain from a Strategic Perspective” is now available. It’s worth your time to watch it. There is a little something for everyone.