Unstable snowpit tests targeting Jan 4 layer on Carpenter Peak.

We snowmobiled up to Carpenter Ridge today and toured the area to assess wind slabs near treeline and to assess the Jan 4 crust/facet layer below treeline.

In this area today, signs of unstable wind slab were difficult to find. Stepping on and kicking at numerous cornice and other wind features produced only very minor cracking. Some very shallow, 4 inch deep wind slabs had failed in response to natural cornice collapse. Collapsing cornices adjacent to these small wind slabs did not produce additional wind slab failures. We looked into the major avalanche paths on Carpenter Peak and across at the north side of Castle Peak we did not see any evidence of recent slab avalanches.

We dug two testpits in below treeline terrain to assess the Jan 4 crust/facet weak layer. In the first snowpit we dug, snowpit tests did not did not show failure on or indicate likely propagation on this weak layer. At this location (see screenshot for site info) HS was 169 cm, Jan 4 crust at 107 cm, base of slab 4F hard over 4F hard facets below Jan 4 crust. ECTN within storm snow, ECTX on Jan 4 layer. PST 46/100 sf @ 106 cm.

At the second snowpit location (lat/long for this ob, N aspect 8,260', below treeline), tests showed failure on facets below the Jan 4 crust and indicated likely propagation along the weak layer. HS was 184 cm, Jan 4 crust at 130 cm, base of slab 1F hard over F+ hard facets below the Jan 4 crust. ECTP-22 @ 128 cm, PST 37/100 end @ 128 cm.

Jan 4 layer appears to be gaining strength, but not at equal rates in all areas which is typical for layer like this.