21-22

A snowmobile triggered wind slab on small slope in the northern Bridgers on 1/22/22. 

A layer of surface hoar that was buried by the recent snow in the southern Madison Range. Photo (1/22/22): G. Turnage

Today we toured into the Divide Cirque. We observed multiple small loose dry avalanches that released from steep rocky terrain while approaching the cirque.

We found 35 cm of fresh snow and were surprised with multiple unstable pit results (ECTV, ECTP8) at 9450 feet on a SE aspect of Divide Peak. 11 other skiers had skied the slope without any signs of loose dry avalanches.

We backed off of Divide Peak and found fresh snow that bonded well to windcrust on non solar aspects on Hyalite Peak.

From email on 1/22/22: "This morning (20220122) I was ascending a steep North facing couloir up the N summit of Republic Mountain and on ascent (boot packing) about 1/2 way up the line I triggered a small soft slab from that propagated around the rock I was tucked behind, 40M above me and and 20M across. Luckily, my ascent line was sheltered from any above exposure and I was not caught or carried in anyway. The crown ranged from 8cm where I triggered it to an estimated 25cm at its deepest. The avalanche ran an estimated 200M.

Dug a pit on the southwest face of meridian before attempting to ascend a couloir. The pit was 70cm deep, recorded ECTP6 at 20cm on the interface between the new and old snow. Then had an ECTP19 at 50cm on facets on the ground. We decided to not ski this aspect. Dug another pit on the way up meridian on a west facing slope and had no results, snow was 170cm deep. 

From email 1/22/22: "Several dry loose naturals on Climax in steep terrain. Perhaps from Thursday or Friday?" Photo: N. Hance