Persistent slab obs and sluffs

CB Avalanche Center 2015-16 Observations

Location: Paradise Divide Area
Date of Observation: 01/10/2016
Name: Zach Guy
Subject: Persistent slab obs and sluffs
Aspect: North East, East, South East, South
Elevation: 9,000-11,400 ft

Avalanches: On steep slopes that had avalanched previously, we skier triggered two sluffs that ran far, gouging to the ground, and could have knocked you over or buried you in a terrain trap. L-AS-R1-D1.5-O
Weather: Few clouds, cold temps, light northerly winds without snow transport.
Snowpack: About 4″ of settled storm snow, over crusts on southerly aspects (up to 2″ thick on steep S, thinner on SE) and facets on northerly aspects. No signs of wind loading or slabbiness in new snow.
Most paths on the northern half of the ridge ran naturally last month with crowns still visible, leaving a structure comprised of 1 -2′ of low density, faceted snow over ground/bedsurfaces. Dug one crown profile on a windloaded NE aspect near treeline, from an Xmas cycle slab avalanche (Photo #1). 95 cm of slab, mostly 1 finger rounds, over fist hard facets. Propagating results. (ECTP 16, Q1 SC, 95 cm deep) Dug another profile on a SE aspect near treeline, 28 degree slope (Photo #2). About 70 cm of faceted 4F to F snow, over 4F moist facets. No test results over the basal layer, but clean propagation in facets below the thin crust near the surface. Not an issue now but could be in the future. (ECTP1, Q1, SC, 10 cm deep).

NE aspect near treeline.  ECTP16, Q1, SC results on fist hard depth hoar 95 cm deep.

NE aspect near treeline. ECTP16, Q1, SC results on fist hard depth hoar 95 cm deep.

SE aspect near treeline. No results except propagation below the near-surface crust.