Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, March 2, at 7:30 a.m. This advisory does not apply to operating ski areas. Mark, Eric and I want to thank everyone who attended the fundraiser dinner at Montana Ale Works last night. All proceeds benefitted the Friends of the Avalanche Center.
Yesterday was a snow free day. West winds decreased and are currently averaging 15-20 mph with gusts to 35 mph. Under partly cloudy skies the temperature dropped last night to 20F from yesterday’s high near 30F. Today will begin with mostly sunny skies, yet clouds will increase. Temperatures will climb to near freezing as winds remain west to southwest at 20 mph. Late tonight a spit of snow will drop a trace to one inch in the northern mountains and 1-2 inches in the south.
The Bridger, Madison and Gallatin Ranges, the Lionhead area near West Yellowstone, the mountains around Cooke City and the Washburn Range:
On Monday, winds gusted to 60+ mph scouring, sculpting and drifting. The high velocity winds did a better job of stripping than loading slopes. Yesterday the speeds calmed and temperatures warmed to near freezing which helped cement many of these newly formed slabs in place. The Big Sky Ski Patrol tried releasing a few hard slabs without luck. Nevertheless, strong mid-mountain winds from the south loaded many gullies and edges of paths, which could still be triggered. The avalanche fatality in Truman Gulch two weeks ago was on the heels of a similar wind event that created a deep hard slab on the edge of a gully.
My travel advice today is simple: be careful getting onto hard slabs at the ridgelines or in gullies. This includes cornices. These have grown substantially in the past weeks making it harder to identify where they may break. It’s hard to believe that a piece of snow weighing thousands of pounds would break under the weight of a 150 pound person, but they do. Besides risking injury (and soiling your pants) if you surf one down, they can also trigger avalanches. Outside Cooke City on Sunday, I saw two slides that released from natural cornice drops (photo 1, photo 2).
The snowpack throughout our advisory area is lacking widespread weak layers. There are still a few isolated areas where unstable snow could exist, but these are few and far between. On Sunday a snowboarder triggered a slide on a small, steep, east-facing slope (photo). Faceted grains on an ice crust were the culprit, but this layering seemed unique to this spot (snowpit profile) and I could not find it elsewhere.
For today, the avalanche danger is rated MODERATE on all recently wind-loaded slopes. Slopes spared a wind-load will have a LOW avalanche danger. And remember, a low danger does not mean no 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.
PHOTOS, SNOWPITS, VIDEO and SURVEY RESULTS
1. We’ve recently uploaded more photos and snowpits to our web site.
2. We’re creating a series of “How To…” stability test videos. So far we’ve made clips on performing a CT and ECT. There are located under <Stability Tests> on the Resources page.
3. The results from our survey are posted online. Thanks to all who participated. You can check out the results at http://bit.ly/fpLuSi.
Upcoming Events
SATURDAY: Pinhead Classic
The 30th Annual Pinhead Classic is on this 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.