Oh-Be-Joyful Basin Crowns

CB Avalanche Center 2016-17 Observations

Location: Crested Butte Area
Date of Observation: 12/20/2016
Name: Zach Guy
Aspect: North, North East
Elevation: 12200-9200 ft

Avalanches: See photos. Got a humbling reminder that avalanche crowns are always bigger in person than viewed from afar, and I underestimated the size of some crowns in previous obs. The crown(s) in Redwell and the Shield are up to 8 feet thick (pencil hard slab over 1mm facets, 4F+ to 1F-). Debris ran impressively far into Redwell Basin. HS-N-R3-D3-O. The slide in Climax Chutes ran nearly full track to the valley and snapped trees. SS-N-R3-D3-O. The Red Lady crown is up to 6 feet thick. Report to come. Observed a dozen or more loose snow avalanches that ran naturally on sunny aspects today or yesterday, triggered by solar/warming. Mostly D1 to D1.5 in size.
Weather: Light winds, few clouds, mild temps.
Snowpack: We descended a NE slope above treeline that had flushed during the cycle with no signs of instability. These slopes now have thin snow coverage that will likely facet out again, making for greater variability in the alpine and some repeat offenders.
Dug two pits below treeline on NE aspects, one above a crown in Washington Gulch and one in Oh-Be-Joyful Basin. The crown profile showed, hard non-propagating results (ECTN25, BRK) on 4F facets near the ground.  The other showed hard, propagating results (ECTP27, SC) on F+ facets near the ground. Both slabs were about 80 cm thick.

Previously unobserved debris off of the west face of Gothic. Couldn’t make out a crown.

Redwell Basin Crown.

Crown above “The Shield” was up to 8 feet thick, pencil hard.

Debris from Redwell Basin slides reached the point where I took this photo from.

Observed a number of fresh loose snow avalanches today. And there is also a crown from the last avy cycle in this shot.

NE aspect BTL. ECTP27, SC on F+basal facets.

Extent of debris below Climax Chutes.