Good Morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Saturday, March 4th at 6:15 a.m. Today’s advisory is sponsored by Cooke City Motorsports and the Pinhead Classic. This advisory does not apply to operating ski areas.
This morning there is no new snow to report. At 5 a.m. mountain temperatures range from the low 20s to low 30s F and winds are blowing 15-30 mph out of the W-SW with ridgetop gusts pushing 50 mph around Hyalite and Big Sky. Today, temperatures will warm into the upper 30s to low 40s in the Bridger Range and low to mid 30s elsewhere. Winds will remain moderate to strong out of the W-SW. There is an increasing chance of precipitation today, mainly in the southern Mountains. Big Sky, West Yellowstone and Cooke City could see 1-2” by tomorrow morning.
Warm weather yesterday with little wind helped promote stability. Yesterday, Alex and I skied near Hebgen Lake and found the snow surface to be damp on all but northerly aspects. Today, a melt-freeze crust will be present on sun exposed slopes. This will create rough riding but stable conditions. It will also limit snow available for transport. Although winds picked up overnight, it’s unlikely there was an increase in wind slab development.
With that said, wind loaded slopes are main avalanche concern today. Areas of wind drifted snow that formed earlier in the week could still be problematic. While these have had to time to adjust and stabilize, they could still fail under the weight of skier or rider. Yesterday, a skier outside of Cooke City observed natural wind slab avalanches in upper elevation terrain. This is a good reminder that wind loaded slopes should not be trusted. This includes large cornices near the ridgelines. These have grown monstrous over the course of the season and should be given a wide berth both on the ridgelines and on the slopes below.
Outside of wind loaded slopes, the snowpack is mostly stable. Yesterday, Alex and I did not observe any signs of instability near Hebgen Lake (video). The weak layer buried 1.5-3’ feet deep in the southern ranges is getting stronger and less reactive. While the snowpack is trending towards stability, common sense and good travel procedures should always be applied when riding in avalanche terrain.
Today, human triggered avalanches are possible on wind loaded slopes which have a MODERATE avalanche danger. Non-wind loaded slopes have a LOW avalanche danger.
Alex will issue the next advisory tomorrow morning by 7:30 a.m.
We rely on your field observations. Send us an email with simple weather and snowpack information along the lines of what you might share with your friends: How much new snow? Was the skiing/riding any good? Did you see any avalanches or signs of instability? Was snow blowing at the ridgelines? If you have snowpit or test data we'll take that too, but this core info is super helpful! Email us at mtavalanche@gmail.com or leave a message at 406-587-6984.
Beacon Training Park at Beall: Open and free to the public for avalanche beacon practice seven days a week from 9 a.m. to 8 p.m., southeast corner of Beall Park in Bozeman (photo).
COOKE CITY
Weekly rescue training and snowpack update, 6:30-7:30 p.m., Soda Butte Lodge on Friday, Lulu Pass Road for field location Saturday (Look for the yellow sign).
Bozeman
Today! Pinhead Classic, Proceeds to benefit Friends of GNFAC. More info here.