Northern Gallatin
Small new snow avalanches at Bridger
Thursday, November 21:
1. "I observed 2 natural avalanches on the slopes between the Apron and Ramp. No ski tracks in those areas. I thought I took a picture but didn’t. Looks like they both started in the rock bands below the ridge. One was small and the other was considerably larger. Hard to know if they ran today or yesterday. Looked like it was just new snow. Pretty much east aspect."
2. "Toured up to the ridge at Bridger today and traversed into Bridger Gully. At around 8,000' in the trees above the most prominent snowfield, my partner and I observed very small dry sluffs confined to the new snow. Bellow Bridger Gully, my partner was able to release a slide while traversing through rocks above his intended line. This was on an east-southeast aspect at 7,500'. Snow just a few degrees more to the east was dryer. The snowpack nearby thinned greatly on the east-southeast aspect.
Wednesday, November 20:
1. " Noted some activity (D1-D2) isolated to the new snow around rock features and ridgetops that were wind-affected. Our pit revealed a weakening and thin snowpack due to the drier weather, however, the facet growth at the ground has remained fairly slow and has maintained moisture."
Skiers near Mt. Blackmore got unstable test results near the top of a 125cm deep snowpack. Photo: L. Peters
On Thursday 11/21 skiers at Bridger noted: "...some activity (D1-D2) isolated to the new snow around rock features and ridgetops that were wind-affected..." Photo: G. Antonioli
On Thursday 11/21 skiers at Bridger noted: "...some activity (D1-D2) isolated to the new snow around rock features and ridgetops that were wind-affected..." Photo: G. Antonioli
Forecast link: GNFAC Avalanche Forecast for Mon Nov 25, 2019
From obs.: "I went skiing at Bridger today,... There was 4-5” of new snow, which was sitting on a firm surface. The wind had done some work, and I was able to break off a few shallow (6”) wind slabs in the first 100 feet or so off the ridge." Photo: A. Schauer
Forecast link: GNFAC Avalanche Forecast for Thu Nov 21, 2019
A skier on Saturday (11/16) took the time to dig a quick pit about 200' below east ridge of Mt Blackmore. He found about 2.5 feet of snow with a few crust layers. Photo: K. Stewart
Forecast link: GNFAC Avalanche Forecast for Mon Nov 18, 2019
Rivers of loose snow avalanches in Flanders Drainage
From Doug Chabot:
I went ice climbing in Flanders and got hit with a graupel storm (0830) which avalanched off the climbs on east-facing slopes for over an hour. It was pretty spectacular and we found knee deep graupel (small, ball-bearing like grains) 200 vertical feet from the bottom of the cliffs. The climbs that we saw this on were Big Sleep, Bobo Like and Killer Pillar. The snow appears to be sliding on a razor thin ice crust under the 3" of new snow that fell last night, which was dense (estimated 15%).
I dug a hand pit to the ground and found 2' of mostly solid snow (no obvious facets) with a couple ice crusts in the upper third. A CT cut with a ski pole yielded no fractures. Elevation 8,000', east aspect.
From obs: "Went for a tour up to Hyalite Basin. No recent sightings of avalanche activity in the basin. There was substantial wind effect on East aspects at 9,000 feet including a dense 3 inch wind layer that was present up to the saddle, which did not propagate in our ECT. We observed a crust layer on south aspects at 7,000 which likely formed before the most recent snow." Photo: Tommy Saulnier
Forecast link: GNFAC Avalanche Forecast for Mon Nov 18, 2019
Small wet avalanche in Beehive
From an email: "I observed a wet loose avalanche that most likely occurred yesterday afternoon. Occurred at an elevation of 8,900' on a WSW aspect, along the runout of a chute sometimes referred to as "the gem". It wasn't very large, but it ripped out to the ground in sections and looked like it could do some damage if caught off guard. I assessed the snowpack next to the small slide, and found a snowpack of only 30 cm composed of facets from 0-14 cm above the ground (F hardness), a crust of large bonded grains from 14-16 cm above the ground, small facets / rounding facets from 16-23 cm above the ground, a rain crust from 23-27 cm that blended into wet snow on the surface becoming slabby in the afternoon sun."