RH at 43m has been bad for a while. Looking back through the plots, the looks like it failed on the night of Apr 24 25 during a period of near 100% RH.
http://www.eol.ucar.edu/isf/projects/BEACHON_SRM/isfs/qcdata/plots/2011042420110425/trh_2011042420110425.png
