Northern Gallatin

I did a loop around Alex Lowe and Blackmore today, and really did not see a whole lot. There was a 5-10mph breeze near ridgelines, and other places were dead calm. This was not the Hyalite I am used to! I noticed a number of small to medium natural sloughs, some of which could have had the power to knock someone over. But overall, I did not see any significant signs of instability. 
I dug a pit at 9400’ on the east face of Alex Lowe, and went down a meter or so. The newest low-density snow was sitting on top of a firm, 5cm crust, which sat over 5-10cm of 4F snow. This crust varied in firmness and depth in different places throughout the day, but I think it would be hard to trigger something through it, for now. Everything I saw below that was a dense (1F), very cohesive slab. An extended column failed at 14 on the 4F/1F interface, but did not propagate. I think this layer could become more reactive if we get heat or more snow, but it seems stubborn for now. It is worth noting that it was about -15F when I dug this. 
At lower elevations, the snowpack is faceted and weak, and I couldn’t step off my skis without sinking almost to the bottom. The skiing was phenomenal!

East winds are stripping snow from an area typically loaded by prevailing winds. Photo: E. Schreier

Today I toured up Mt Ellis and skied down a northeast aspect. I gained the north ridge around 11am, and there was a strong wind from the north (see photo). When checking out the snow, the effect of this wind was quite apparent with only about 10cm of recent snow high up on the ridge. Further down, and in the trees, the new snow total increased to 15-20cm. Unfortunately, my dog disagreed with my choice of location to test the snow and continued much further downslope, but I was able to get a few hand pits in. The new snow bonded quite well, and I observed only minor sluffing on the descent. 

Today we skied on north-facing aspects in the basin southwest of Blakcmore Lake. Snow started falling around noon and, by 1pm, it increased to approximately 1in/ hour. We tested the snow on northern aspect at ~9250ft. We observed an HS of 188cm (see attached snowpilot for hardness). At this location the snow has stayed well protected from recent wind loading and warmer temps, and the layer underlying the new snow showed no signs of propagation (ECTN22 @145cm). We did observe, however, a moderate shovel shear with a Q2 shear on this same layer. With the rapidly changing weather, we avoided wind loaded slopes for the day and will be carefully watching the conditions as the snow falls. 

Two skiers came across a natural avalanche while touring on the southeast side of Arden peak seen from Maid of the Mist basin. The avalanche appeared to be around 100 feet wide at the crown and ran all the way down the bowl until things flattened out -- maybe 700 feet. The avalanche appeared to be maybe a foot deep at the crown, appeared to have broken on a wind slab on the fresh snow. We dug a hasty pit that showed weakness on that same layer of new snow around 10-12 inches deep at the interface with the previous layer. We were planning to ski the Pinner on the north east side Arden peak, but upon seeing evidence of instability we scaled back our objective and skied Maiden bowl. 

This is the slope that avalanched and killed a snow bike rider (motorized) on 2/19/22. Photo is from the Search and Rescue team who were leaving the site as it was getting dark, and did not have time to gather more info. Click link below for more details. Photo: B. Zavora