Good Morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Advisory issued on Sunday, February 25th at 7:00 a.m. Today’s advisory is sponsored by Montana Ale Works and Highline Partners. This advisory does not apply to operating ski areas.
Since yesterday the Bridger Range got 8” of low density snow, Hyalite got 1”, and elsewhere 3-4”. This morning, wind is westerly at 25-30 mph with gusts of 40-50 mph and temperatures are single digits F. Today, strong west wind will continue with temperatures in the teens F. Snow will return this afternoon with 5-8” in the mountains overnight and more through tomorrow morning.
New snow across the advisory area varies from 3-9” deep and equals .2-.3” snow water equivalent (SWE) even where deepest. Strong westerly wind today will drift new snow into slabs up to 2’ thick that are possible to trigger (video). Be cautious of wind loaded slopes near ridgelines, on steep rollovers, and around cliffs (photo, photo). Look for cracking and collapsing of the new snow as a clear sign to avoid steep, wind loaded slopes. Wind earlier this week drifted snow into dense slabs on top of lower density snow (video). These can be identified where a ski pole or boot punches through a hard slab into ‘hollow’ snow below. Skiers in Hyalite yesterday found this unstable structure, and avoided steep wind loaded slopes. Cornices along ridgelines are huge and continue to grow (photo). Keep a far distance from the edge and avoid slopes directly below cornices.
On non-wind loaded slopes the snowpack is generally stable and lacks widespread weak layers. Eric was at Hebgen Lake on Friday and found good overall stability (video). On some slopes it is possible to find a buried weak layer of facets or surface hoar 2-3’ deep. In Cooke City, Eric found a layer of facets 2’ deep that produced unstable results in stability tests last Tuesday (video). The new snow is a small amount of weight added to any lingering weak layers, but it is worth digging 3 feet to look for and assess stability before riding steep terrain. Where new snow is deepest, dry loose avalanches are possible and can be harmful if caught above consequential terrain like cliffs.
Today, strong wind and new snow create fresh drifts that are possible to trigger and avalanche danger is MODERATE.
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
Feb. 28th, Know Before You Go avalanche awareness, 7:00 p.m. @ Procrastinator Theater, MSU
March 2nd and 3rd, SheJumps Companion Rescue Clinic, Info and Register HERE
March 2nd, Avalanche Awareness, 7-8:00 p.m., MAP Brewing Bozeman Split Fest
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
Every Friday and Saturday, Current Conditions Update and Avalanche Rescue, Friday 6:30-7:30 p.m. at The Soda Butte Lodge in February. Saturday anytime between 10-2 @ Round Lake.
A good partner is essential for a safe day in the backcountry. This recent article from Backcountry Magazine provides some tips on how to find and be a safe backcountry partner.