Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, March 29, at 7:30 a.m. Montana Fish, Wildlife and Parks Snowmobile Program sponsor today’s advisory. This advisory does not apply to operating ski areas.
Before the storm ended yesterday morning it snowed three more inches in Hyalite and one to two inches everywhere else. Temperatures rose to the mid 20s before dropping to the teens last night. Winds increased from the west to southwest and are now blowing 10-20 mph. The sun will poke through partly cloudy skies this morning as mountain temperatures rise to near freezing. A moist, Pacific flow, pushed by the jet stream, will creep in late this afternoon and bring snow showers totaling a couple inches by 6 a.m. and more on Wednesday.
The Bridger, Gallatin and Madison Ranges, the Lionhead area near West Yellowstone, the mountains around Cooke City and the Washburn Range:
Yesterday’s snowstorm dropped 6-12 inches of snow in most areas under calm skies. Later in the day winds started to pick up out of the west to southwest. Recent wind-loading is our biggest stability concern today. Drifts of soft slabs will be sensitive to triggering near the ridgetops. I do not expect to see widespread avalanches, but I do think folks could trigger slides if they let their guard down.
In the last two weeks over four inches of water has fallen in the mountains. That’s over four feet of snow. Aided by warmer temperatures the storm snow settled and compressed quickly. Big snowfalls are Mother Nature’s stability test. Slopes held this load and avalanche activity was minimal. Eric found deep, stable snow in Bostwick Canyon in the Bridgers on Sunday (video), and also detected good stability during his tour of Beehive and Bear Basins yesterday. Mark found safe conditions outside Cooke City on Saturday and I also had stable snow around Taylor Fork last week. This pattern of stability spans entire mountain ranges. Our primary avalanche concern is limited to new snow which means we do not have to dig deeply to test the snowpack.
Other concerns, besides wind-loaded slopes, are cornices and thinner snowpacks. Cornices have grown to monstrous proportions. These can break suddenly and further back than anticipated. Besides crushing you, these beasts can trigger relatively strong slopes. Thin snowpacks, those measuring four feet or less, have more facets and are generally weaker, but are hard to find.
For today, throughout southwest Montana, the avalanche danger is MODERATE on all wind-loaded slopes and LOW on all others.
I 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.
Ride in honor of Steve Green
This Saturday, April 2nd, is a memorial ride on Buck Creek Ridge in honor of Steve Green who died in an avalanche last April in McAtee Basin. Meet at 9:30 a.m. at the Buck Creek parking lot near the Corral. Click HERE for more information.
Last Advisory
The last avalanche advisory of the winter is Sunday, April 10th. Count on a huge snowstorm of biblical proportions on Monday the 11th. Guaranteed.