Route & General Observations
Ascended to 2750′ on Tenderfoot to dig near the 2/27 avalanche. Found hard wind slabs in many areas exposed to the wind above 1900′ sitting on a variety of persistent weak layers.
None. Old avalanche on North aspect of TriTip that occurred sometime since CNFAIC's last visit to Tenderfoot Feb. 28.
Partly to mostly cloudy, calm winds, no precipitation, 20s F at valley bottoms and teens at ridgetops.
0.5" of new low density snow.
Handpits at 1900' were failing on isolation or easily 14" below the surface on facets over a melt freeze crust.
Pit at 2300', West aspect, 21 degree slope. CT18 SC failed 39 cm below surface on a mix of decomposing 9mm Jan. 25 buried surface hoar (BSH) and mostly 1 mm facets. ECTX.
Pit 1 at 2500', NW aspect, 31 degree slope, HS=174 cm. CT23, CT24, ECTN27 failed ~45cm below surface on Jan. 25 BSH and 1mm facets. ECTX. There was a 2cm MFC only 5cm below this layer with facets just below the crust. No failure on this layer in stability tests. Found the New Year's BSH 100cm below the surface. Did not perform tests on this layer due to hemlock branches in lower portion of pit.
Pit 2 at 2500' (right next to flank of avalanche), NW aspect, 31 degree slope. CT12 & 15 PC and ECTP25 failed 32 cm below surface on 1mm facets. Jan. 25 BSH and the MFC/facet layer mentioned above were found but not reactive in tests.
Pit 1 at 2750', W aspect, 20 degree slope, HS=135 cm. CT25, CT23, ECTN12 failed 20-25cm below the surface on Jan. 25 BSH and 1mm facets. There was also a 1 cm MFC with facets below the crust 25-35cm below the surface. No failure on this layer in stability tests. Both of these layers were not planer, likely formed on variable surfaces (sastrugi), but were continuous through pit wall.
Pit 2 at 2750', W aspect, 20 degree slope. CT29 SC failed down 23 cm on Jan. 25 BSH and 1 mm facets. CTN x 2. MFC/facets mentioned above were found in pit but not reactive in tests.