Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, March 24, at 7:30 a.m. Soda Butte Lodge and The Bountiful Table sponsor today’s advisory. This advisory does not apply to operating ski areas.
I’m not picky -- rain in the valleys and snow in the mountains is just fine. This morning at 6 a.m. there is nine inches of new snow up Hyalite and 6-7 inches everywhere else. All the mountain ranges got hit and it’s still snowing. Mountain temperatures are 15-20F, the coldest they’ve been in weeks. Winds are westerly at 15 mph with gusts of 30 mph at the ridgelines with Cooke City getting gusts of 40 mph. Today, temperatures will warm into the high 20s and winds will remain westerly averaging 15-20 mph. Snowfall will become sporadic and by tomorrow morning I expect an additional 4-6 inches in the mountains making it one of the biggest storms in the last two months…which is nothing to brag about, but enough to call in sick (cough, cough). Better charge the GoPro.
Bridger Range Madison Range Gallatin Range Lionhead area near West Yellowstone Cooke City
It’s pretty simple: new snow and wind-loading are creating today’s avalanche danger.
At high elevations the new snow fell onto a frozen snow surface on all but the most north facing slopes (video). The snow is dense and measuring .6 to .8 inches of snow water equivalency. Snowfall started with temperatures near 30F which got colder last night making for a “right-side up” storm: denser snow underlying lighter powder. Late yesterday the Big Sky Ski Patrol was able to get thin slabs to easily avalanche with only one inch of new snow. With more than six inches this morning, sluffing and triggering soft slabs will be likely throughout our area, especially on wind-loaded slopes.
Be mindful today because the likeliest time to trigger avalanches is during a storm. Slopes you skied or rode with impunity yesterday are no longer a good bet. Conditions changed and your sweet, steep line may not be safe for the next few days. Recent avalanche activity or cracks shooting out from under your feet are a clear warning of instability. For today a CONSIDERABLE avalanche danger exists on all wind-loaded terrain as well as any slope steeper than 35 degrees. A MODERATE danger exists on lower-angled slopes sheltered from wind-loads.
As a friendly reminder, Considerable danger means that human triggered avalanches are likely, so proceed cautiously.
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.