Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, February 6 at 7:30 a.m. The Yellowstone Club Community Foundation in partnership with the Friends of the Avalanche Center sponsor today’s advisory. This advisory does not apply to operating ski areas.
At 5 a.m. there’s no new snow to report. Westerly winds are averaging 10-15 mph with gusts to 30 mph under clearing skies. Mountain temperatures are near 20F. Today will be partly cloudy as winds remain the same and temperatures rise into the high 20s. High pressure is building and there will be little chance of precipitation over the next few days.
Bridger Range Northern Madison Range Cooke City
As the days pass and we get further away from last week’s heavy snowfall the overall avalanche danger is decreasing. This is good news. But there are lingering instabilities which are not obvious, and that’s the bad news. Human triggered and natural avalanche activity spiked over the weekend (many photos), but even yesterday, the Big Sky Ski Patrol had full depth avalanche releases during control work on old faceted snow. And on Monday, a snowbike triggered a 100 foot wide avalanche in Sheep Creek outside Cooke City.
There are weak layers in the snowpack: sugary facets near the ground on slopes that were less than three feet deep before the recent storm (video); and smaller grained facets that were at the surface, but now buried. Dig and search for these layers. During periods of nice weather, great riding conditions and decreasing avalanche danger, it’s easy to get complacent. Avalanches can still be triggered, especially on slopes that were wind-loaded or where the snowpack doubled in depth with last week’s storm. Consequently, the avalanche danger is rated MODERATE on all slopes today.
Southern Madison Range Gallatin Range
Lionhead area near West Yellowstone
The mountains south of Big Sky to West Yellowstone, as well as the entire Gallatin Range, which includes Hyalite Canyon, have widespread instability. In the Gallatin Range 2-3 feet of snow fell and stressed many slopes to their breaking point, especially those with a thinner snowpack (i.e. Mt. Ellis and Mt. Blackmore). In the southern Madison Range weak surface snow was buried under 1-1.5 feet which produced many avalanches. This layer is still a problem. Yesterday, Mark rode around Taylor Fork and Cabin Creek and had these facets propagate in two out of his three snowpits. He was on the hunt for instability. One stable snowpit is not enough evidence of safe conditions, especially when we are confident a weak layer exists. Dig another, and another. Natural avalanche activity on Friday, human triggered slides on Sunday (photo), poor stability test scores yesterday and a known persistent weak layer all point to a CONSIDERABLE avalanche danger on slopes steeper than 35 degrees and a MODERATE danger on all other terrain.
Mark will issue the next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations drop us a line at mtavalanche@gmail.com or call us at 587-6984.
OTHER MOUNTAIN RANGES – Heads Up
In nearby mountain ranges (like the Crazy and Absaroka Ranges) just outside the advisory area we’ve been receiving reports of both natural and human triggered avalanches. We do not have data on these areas, but it sounds like conditions are generally more unstable than what we’ve seen in our advisory area. Many of these ranges had a very thin snowpack in January that became very weak and faceted.
February 16: 11th Annual King and Queen of the Ridge
The 11th Annual King and Queen of the ridge Hike/Ski-a-thon fundraiser is Saturday, February 16. The event supports avalanche education. Enter as an individual or a team. Collect pledges for the number of hikes you can do in five hours. Kids and families are encouraged to hike too! Prizes will be awarded to the most hikes (1st, 2nd, and 3rd); most money raised, most laps for a team, most money raised for a team. More Information / Registration Form
The Friends are teaching a free Companion Rescue Course in Big Sky, at Grizzly Outfitters, on Friday, February 8 from 6-8 p.m., followed by a field session the next day from 10 a.m. to 2 p.m. Space is limited and pre-registration is required: https://ticketriver.com/event/5830-companion-rescue-clinic-for-skiers-&-boarders
In West Yellowstone, on Friday February 8th, the Friends are giving a 1-hour Avalanche Awareness for Snowmobilers lecture at 7pm at the Holiday Inn.