Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, February 23, at 7:30 a.m. On Site Management, in cooperation with the Friends of the Avalanche Center, sponsor today’s advisory. This advisory does not apply to operating ski areas.
At 7 a.m. the USFS computers do not have internet access and we have not been able to update all the weather pages.
Since yesterday morning the southern mountains picked up five to seven inches of snow while the northern ranges got two inches. With mountain temperatures in the single digits, westerly winds are averaging 15 mph with gusts to 30 mph. Today will be mostly cloudy with a few flurries and temperatures only rising to near 10F. Tonight the mountains should get two to four inches of new snow with light southwest winds and temperatures dropping near zero.
The Bridger, northern Madison and northern Gallatin Ranges:
This passing storm had a poor showing in the northern mountains and only dropped two inches. I had high expectations, but the storm just gave us a peck on the cheek. Without much new snow and winds blowing light from the west-southwest, the snowpack will not be under much stress. Mark toured up Hyalite to the Flanders Mountain weather station yesterday. He found mostly stable snow and wind slabs becoming more stubborn and less hair-trigger. He was unable to get the snow to fracture in his stability tests. There may still be isolated areas where a thin layer of facets two feet under the surface could avalanche, but this concern is not widespread. Given the 16-24 inches of snow that’s fallen in the past seven days with wind, the avalanche danger today is rated MODERATE.
The southern Gallatin and southern Madison Ranges, the Lionhead area near West Yellowstone, the mountains around Cooke City and the Washburn Range:
In the last 24 hours, the southern mountains got a half an inch of snow water equivalency (SWE) which translates into five to seven inches of snow. This is on top of two feet of snow (two inches of snow water) they’ve gotten in the last week. This load has been added gradually which helps the snowpack adjust and stabilize to the stress of this snowfall. Winds are blowing west-northwest at 15-30 mph, strong enough to continue loading the lee sides of ridges. On Monday, I was in the Lionhead area and had a layer of small grained facets fracture in my snowpit, something I was not expecting. This layer was created February 2nd and is not an issue on most slopes. But the fact that I got it to propagate in my test means it’s worth looking out for (video) (photo). With continued snow and winds, avalanches are likely to be triggered on wind-loaded slopes which have a CONSIDERABLE avalanche danger. All other slopes have a MODERATE danger.
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.
New Snowpits Page
In response to our survey we added a new page to the website with images of our snowpit profiles. This page is under the Resources/Other Info tab at www.mtavalanche.com/snowpits
3rd Annual Montana Ale Works Fundraiser
Tuesday, March 1 at 6:00 p.m. in the Railcar at Ale Works in Bozeman
Cost: $25 to benefit the Friends of the Avalanche Center
Details: Chef Roth at Montana Ale Works is creating tapas style servings that will be paired with select beer from Lone Peak Brewery. More information HERE.
Pinhead Classic
The 30th Annual Pinhead Classic on is Saturday, March 5th. “Gangsters and Flappers” is this year’s costume theme, so come dressed up to race, socialize and wind great prizes. Registration is $30 but get you all sorts of cool stuff. All proceeds benefit the Friends of the Avalanche Center. Check out the website http://pinheadclassic.com for details.