Northern Gallatin

Blackmore Lake, NE Aspect

Date
Activity
Skiing

Yesterday we tested and skied a well-protected, NE-facing line above Blackmore Lake. There were strong winds during our approach and we observed evidence of wind loading on northern aspects. By around 2 pm, wind speed and wind loading reduced significantly. At our pit location, we observed a thin wind crust (1-2cm) that moved quite readily. This layer did not move during stability tests and did not propagate while skiing, but released readily while skiing. At the bottom layer of the snowpack, we noted that the grain size increased since our visit to the area last weekend, and the faceting in this layer was much more apparent particularly at the bottom of the layer (see photo). 

Region
Northern Gallatin
Location (from list)
Mt Blackmore
Observer Name
Erich Schreier

Recent natural avalanche activity near Moose Jaw creek

Date
Activity
Snowboarding

Observed recent small wind slab avalanches under the ridgeline as well as one larger slide that broke on weak snow near the ground, likely cause by cornice fall. 

Region
Northern Gallatin
Location (from list)
Moose Jaw

Natural Slide and Wind Stripping in Hyalite Basin

Date
Activity
Skiing

Toured into Hyalite basin and found evidence of what looked like an older and large slide on Hyalite peak. Intense wind scouring appears to have taken place, or the slide ripped to the ground. Ample evidence of wind loading and stripping throughout the bowl left us with enough evidence to turn around without digging. We skied lower angle trees out of the basin and then toured into Divide basin. We dug a pit on the sheltered shoulder of the typical skin track to divide peak and got an ECTx. Snowpack was well bonded and congruent to the ground on this specific E-NE aspect and slope Snowpack was about 100-145cm deep in total.

Region
Northern Gallatin
Location (from list)
Hyalite Peak
Observer Name
C Mumford

Bailed to more protected terrain

Date
Activity
Skiing

Submitted via instagram: "Ectp12 and 22 at 85 and ~25-30 cm (less planar) respectively on S aspect we did not ski and bailed from after initial pit ~300m away in slightly more protected terrain yielded ectN. Was dug adjacent to ~33-35 degree slope. Slope is located near the head of Flanders Basin"

Region
Northern Gallatin
Location (from list)
Flanders Creek

Loose snow avalanche Hyalite Canyon, Bobo Like

Hyalite - East Fork
Northern Gallatin
Code
L-N
Latitude
45.44680
Longitude
-110.93600
Notes

At about 10 AM I was belaying my partner on the first pitch of Bobo Like in the Flanders drainage of Hyalite Canyon.  We heard a low rumble and a couple seconds later we were engulfed in snow that poured out of the the pitch 2 gully, and seemed to keep coming for about 5 seconds.  My partner, who was on lead, was lucky enough to be at the base of the vertical ice of p1, so the snow mostly went over his head.  I was off to the side and close to rock at the base and was engulfed in loose snow, but not buried or injured.  We continued up afterwards.  When I was at the top of the second pitch, belaying my partner up, another small loose snow avalanche came down as river of snow, passing me as I hugged the anchor, and washed over my partner while he was on the pitch.  We were fortunate to have both been in positions to handle these avalanches without incident or injury.  In retrospect, the clear day and blasting morning sun likely loosened the snow above the gully and funneled it all down onto us.  After the first avalanche, the sun must have kept moving onto new slopes above, releasing more snow.  Even with a moderate danger level in the avalanche report for the day, with natural avalanches unlikely, we happened to find ourselves in a very specific scenario, with morning sun and a dangerous terrain feature, that still put us at risk.  Hopefully we will use this experience to improve our assessment of risk, terrain, and evolving conditions in the future.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Loose-snow avalanche
Trigger
Natural trigger
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year