Improving snowpack

CB Avalanche Center2016-17 Observations

Location: Paradise Divide Area
Date of Observation: 01/31/2017
Name: Zach Guy
Subject: Improving snowpack
Aspect: North East, East, South East, South, South West
Elevation: 9,200-12,500 ft.

Avalanches: -One couch sized cornice fell off of an East aspect ATL today; didn’t trigger anything.
-A D1 wet loose looks like it ran in last couple days on a S BTL slope
-A number of crowns visible from last week’s avalanche cycle. See photos.
-A D2.5 (or larger?) debris pile below East face of Mineral Point, also from last week. Ran full track.
Weather: Strong winds, variable directions but mostly WNW. Light to moderate transport, mostly saltation, not loading. Mild temps. Few clouds to scattered clouds.
Snowpack: No signs of instability. 5 pits from BTL to ATL, generally with strong structure and no concerning results, even on a slope with buried surface hoar.  Ski pen is 10-15 cm BTL and 5 cm ATL. Slab depth down to 1/19 interface ranged from 50 cm BTL to 10-120 cm ATL, depending on wind patterns.  We ski cut and snowmobile cut a number of steep, suspect rollovers with no results on various aspects/elevations. Winds kept surfaces cool where we traveled; no wet loose concerns. Weak layers at the surface have been worked over by the wind. Here are the pit specifics
1. N aspect. 9,600 ft, in wind sheltered area. Could not ID any surface hoar. Q2 CTM and CTH on mid-storm DF’s. ECTN H on mid-storm DFs. Hard to ID 1/19 storm interface, but it was probably about 50 cm deep.
2. ESE aspect. 10,300 ft, in moderately wind affected area. No surface hoar, no PWL or crusts. Q2 CTM and CTH on DFs. Hard to ID 1/19 storm interface, but it was about 50 cm deep.
3. S aspect. 11,500 ft. 70 cm of 4F to 1F slab over Jan 19 crust. No obvious facets around crust. ECTN H BRK above crust.  HS over 400 cm.
4. NE aspect, 11,600 ft. 90 cm of slab over Jan 19 interface. No PWL. CTH Q2 on mid storm DFs
5. NNE aspect 9,600 ft. Adjacent to previous natural avalanche. Jan 19 SH buried 50 cm deep, well integrated into surrounding DFs. ECTN H BRK on SH. CTH Q2 on SH.

D1. SW aspect BTL

NNE aspect BTL. Adjacent to natural slide from last week.  Note the wind-damaged surface hoar on the surface.

South aspect ATL.

D1 wind slab, a few days old.

Surfaces are stiffened and roughened by winds at all elevations.

D2 NE aspect BTL. Profile #5 dug near this slope.

Recent D1 wet loose. S aspect BTL.

D1.5? NE aspect BTL

D2. NE aspect BTL

D2? NE aspect N/BTL

D2 NE aspect NTL

D1.5 NE aspect BTL

D2. East aspect BTL

Impressively far-running debris piles below Climax Chutes. These crowns reported last week.