Pittsburg

CB Avalanche Center 2017-18 Observations

Location: Crested Butte Area
Date of Observation: 02/15/2018
Name: Ben Pritchett

Subject: Pittsburg
Aspect: North, North East
Elevation: 9,000-10,700′

Avalanches:

Saw 4 D2’s on Schuylkill that ran sometime between Tuesday afternoon and Wednesday mid-day. SS – N – R1/D2 – O

Weather: Snowed pretty much all afternoon, steady. Didn’t accumulate to that much, only an addition 3″ in the PM hours, but certainly made the surfaces soft. HN24 7-10″, measured .7″ SWE.  No significant wind transport observed in the sheltered terrain where we were, but west winds really don’t hit Pittsburg. Probably quite windy elsewhere.
Snowpack: Didn’t get any cracking or collapsing in the new snow, but by mid-afternoon sloughs were running in steep terrain over 40 degrees.
Dug in two places.
1) 10,400′ NE – in a path that avalanched January 12th below the holiday slab (12/23 interface). total HS was ~135cm. ECTP moderate, popping into our pit with a lot of umpf. Scary structure and represents a similar structure to the avalanches observed below, and the recent mention of skier triggered activity in the last 10 days.
2) 10,600′ NE – in a path that had not avalanched this season. Total HS was 170cm. ECTN. Just too deep and slab too stiff for ECT results. PST End 40/135 repeated in a couple tests, with identical results. Also tested both the 12/23 interface (below holiday slab), and the 1/6 interface just above it. Both produced 40/135 results twice, but the block collapsed and slid on the 12/23 interface. These weak layers are pretty deep and not reacting right now, but worrisome if we get a really big load at once. This slow steady snowfall over the past week hasn’t triggered any slides on these weak layers locally.

Photos:

D2 at the end of the trees on Schuykill Ridge. This slide ran between Tuesday PM and Wed mid-day (based on reviewing photos from each of those times). The next path up valley (looker’s right) ran Monday.

Three more D2’s just down valley of the first. All ran as repeat offenders on bed surfaces that re-faceted after the Jan 10-12 avalanche cycle.