PS becoming less reactive but stiffer

CB Avalanche Center 2016-17 Observations

Location: Crested Butte Area
Date of Observation: 02/01/2017
Name: Zach Guy
Subject: PS becoming less reactive but stiffer
Aspect: North, North East, East, South East
Elevation: 9,000 – 10,000 ft

Avalanches: Lots of skier triggered rollerballs on ESE aspects BTL; their first moistening of the week. No new avalanches observed.
Weather: Warm. Increasing thin clouds. Light winds below treeline.
Snowpack: Traveled in two areas near town that held similar snowpack structure to this observation. As we climbed above the inversion, slabs became less faceted, and the recent warming/settling has made the slabs denser and the surface hoar less reactive.  Slightly harder and more propagation in tests (see photos), but we ski cut about 5 steep slopes and couldn’t get anything to move or crack. These same types of slopes were very touchy last week, triggering was almost certain. It seems that instabilities are becoming more isolated, but greater potential for a slide breaking above a skier or a wider avalanche exists now at these locations. The persistent slab structure on SE aspects over the 1/19 interface is changing to a stack of thick crust over faceted snow. No concerns in the morning while the crusts were solidly frozen.  Weak layers on the surface: Small surface hoar and/or near surface facets on most open, shaded aspects. Large surface hoar on a few isolated north facing slopes.

NE aspect 10,000 ft.  32 cm, 4F slab over surface hoar.  ECTP11, SC.  Ski cut this slope where it rolled over to ~38 degrees with no result.
NE aspect 9,300 ft.  CTM, SC, 28 cm deep on SH.  ECTN M on same layer.  F+ slab. Traveled on several slopes up to 35 degrees near this pit and got no signs of instability.
Rollerballs on Southeasterly aspects below treeline.