GNFAC Avalanche Forecast for Thu Mar 2, 2023

Not the Current Forecast

Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Forecast on Thursday, March 2nd at 7:00 a.m. This information is sponsored by Avalanche Alliance and Blitz Motorsports and Yamaha. This forecast does not apply to operating ski areas.

Mountain Weather

Yesterday, 1-2” fell with 3” at Big Sky. Wind is W-NW at 30-50 mph in the Bridger Range and 10-20 mph with gusts of 38 mph everywhere else. Temperatures are in the high single digits this morning and will reach into the 20s F today as wind blows strong from the W at 20-40 mph in the north and 10-20 mph in the south. Expect mostly cloudy skies today and snowfall tonight bringing 1-2” by morning.

Snowpack and Avalanche Discussion

I’m beginning to lose sleep over Cooke City. Alex saw a large avalanche on Henderson Bench yesterday that was released the night before, possibly from wind-loading (obs and photo). Another slide on Miller Ridge might have similar timing (photo). These mountains had snow on 10 of the last 11 days along with strong wind. On Saturday and Sunday, 4 people were caught and partially buried in 3 separate slides (Town Hill, Mt. Abundance, Round Lake). Large, recent avalanches are sprinkled over the range. The wind has died down and the chances of triggering slides has lessened, but is not gone. Tread gently in avalanche terrain, especially on slopes which are wind-loaded. These might not be obvious given the few inches of fresh snow covering layers of wind slab.

The avalanche danger is rated a serious MODERATE

The mountains south of Big Sky to Lionhead have also gotten snow 10 of the last 11 days. Dave was in Taylor Fork yesterday and found an avalanche in Sage Basin that was triggered by a cornice fall (video). It broke 150 feet wide and 3 feet deep on a weak layer of surface hoar that was buried January 10th, which puts the word “persistent” into the term persistent weak layer. Yesterday, skiers on Bacon Rind had poor stability test scores on a layer of weak facets almost 2 feet deep (observation), and I found a weak interface at the same depth at Lionhead on Tuesday (video). With weak layers being found and avalanches breaking early in the week, it is entirely possible to trigger an avalanche today. As Dave advises in his video, be especially wary around wind-loaded terrain and dig, test and only put one person at a time on a slope. 

The avalanche danger is rated MODERATE.

The northern mountains around Big Sky and Bozeman had avalanche activity on Friday and Saturday from a large snowstorm, but the mountains have been quiet since then (Weather and Avalanche Log). Last night's wind will blow snow into drifts which are our primary avalanche concern. Instabilities will be found near the ridgeline. We are not consistently finding buried weak layers which is a good sign, however, it remains prudent to dig and check the upper three feet of the snowpack just to be sure. Coming across a recent avalanche, no matter how small, is a sign of instability. 

For today, the avalanche danger is rated MODERATE

Please share avalanche, snowpack or weather observations via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).   

The mountains have gotten snow 10 of the last 11 days totaling almost 20”. With weak layers being found and avalanches breaking early in the week, it is entirely possible to trigger an avalanche today. Be especially wary around wind-loaded terrain and dig, test and only put one person at a time on a slope. Triggering avalanches, especially in wind loaded slopes, is expected today.

Upcoming Avalanche Education and Events

Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.

TOMORROW! March 3, 9 a.m.-3 p.m., Bozeman Splitfest - Companion Rescue Clinic. Classroom session followed by a field session. More information and registration HERE.

TOMORROW! March 3-5, Bozeman Splitfest. More info and register here.

TOMORROW! March 3 & 4, Companion Rescue Clinic. Online classroom session Friday evening followed by a field session from 10 a.m.-2 p.m. Saturday. More information and registration HERE.

March 9, 6 p.m.-7 p.m., 1-Hour Awareness - Spring conditions. FREE at REI Bozeman.

March 10 & 11, SheJumps - Women’s Companion Rescue Clinic. Online classroom session Friday evening followed by a field session from 10 a.m.-2 p.m. Saturday. More information and registration HERE.

Every Saturday, 10 a.m. - 2:00 p.m. Avalanche Rescue Training, drop in for any amount of time. Round Lake Warming Hut, Cooke City. Free. 

Loss in the Outdoors, is a support group for those who have been affected by grief and loss related to outdoor pursuits. Check out the link for more information.

 

The Last Word

Tragically, a week ago in Wyoming a snowmobiler was buried and killed in an avalanche. Over the weekend in Colorado, two skiers and one snowmobiler were buried and killed. Current details for these accidents are available HERE.

 

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