Good Morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Advisory issued on Sunday, March 4th at 7:00 a.m. Today’s advisory is sponsored by Yellowstone Arctic Yamaha and Yamaha Motor Corp in partnership with The Friends of the Avalanche Center. This advisory does not apply to operating ski areas.
At 5 a.m. it is snowing lightly in Bozeman with no new snow in the Bridger Range and 1” near Big Sky and Hyalite. The mountains near West Yellowstone and Cooke City got 4-6” of new snow since yesterday morning. Temperatures this morning are low teens F and will remain in the teens F today. Wind is east-northeast at 5-15 mph and will shift northwest at 15-25 mph early this afternoon. The mountains will get 4-6” of snow by morning with a deeper dump of cold smoke powder possible near Bozeman and Cooke City.
Over the last three days the mountains near West Yellowstone and Cooke City got 1-2 feet of new snow equal to 1-1.5” of snow water equivalent (SWE). This new snow is a small amount of stress on top of a generally strong, 7-12 foot deep snowpack. Wind loaded slopes and large cornices are the main avalanche concerns today.
On Friday, Eric and I saw huge cornices and avoided wind loaded slopes in Tepee Basin (video), and skiers near Bacon Rind found easy to trigger wind slabs (photo). Moderate south to east wind over the last 24 hours drifted snow into slabs 1-2’ deep. Due to the less common wind direction these slabs may be found in unusual locations like mid-slope and the west side of ridgelines. Stronger northwest wind this afternoon will drift new snow into fresh, easy to trigger slabs. Avoid wind loaded slopes near ridgelines and pillows of snow below cliffs and on convex rolls.
On non-winded loaded slopes avalanches breaking in the new snow are possible, especially as more snow falls today. Avoid steep slopes if you see shooting cracks or collapsing in the new snow and be cautious of dry loose avalanches in consequential terrain.
Today, avalanche danger is CONSIDERABLE on wind loaded slopes. Non-wind loaded slopes have a MODERATE avalanche danger.
The mountains near Bozeman and Big Sky got only 1-2” of new snow the last three days. Strong wind Friday formed drifts near ridgelines, below cliffs and in steep gullies. A skier triggered a small slab yesterday in Hyalite (photo), and on Friday Doug found fresh drifts in gullies. These wind slabs are harder to trigger today, but possible, and especially harmful if caught over cliffs or tight trees.
Large cornices continue to grow and can collapse naturally with new snow and wind or under the weight of a person. Cornices often break farther back than expected (photo). Stay a far distance back from these monsters along ridgelines and avoid slopes directly below.
Stronger wind this afternoon will drift new snow into fresh slabs that are possible to trigger. On non-wind loaded slopes, avalanches breaking in the new snow and dry loose avalanches are possible with greater amounts of snow today. More snow today and stronger wind make avalanches possible and danger is rated MODERATE on all slopes.
If you get out and have any avalanche or snowpack observations to share, drop a line via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).
Upcoming Avalanche Education and Events
BOZEMAN
March 7th, Avalanche Awareness, 6-7:30 p.m. @ REI
LIVINGSTON
March 20, Beer for a Cause Night at Katabatic Brewing, 4-8p.m. A dollar from every pint will be donated to The Friends of the Avalanche Center.
COOKE CITY
Friday and Saturday, Current Conditions Update and Avalanche Rescue, Friday 6:30-7:30 p.m. at The Soda Butte Lodge. Saturday anytime between 10-2 @ Round Lake.
In Dashboard Talks, Episode 7, Alex Marienthal and Doug Chabot provide a few thoughts about why you should read the daily advisory. As the season wears on, don't get "Advisory Fatigue." There is a lot of winter still to come!