Mesospheric winds have been determined from ground-based optical measurements of the nighttime sky emission of the P1(2) lines of X 2&Pgr; OH (8-3) band. The measured winds indicate a 12-hour periodicity with amplitude near 30 m/s, and presumably associated with tidal motions. The frequencies (wavelenghts) of these &Lgr;-doubled P1(2)c.d lines have been measured to be 13 664.444 K (731.6428 nm) and 13 664.311 K (731.6320 nm), with a standard deviation of the mean of 0.001 K (0.00007 nm). The spacing between the two P1(2) lines is found to be 0.1346¿0.00005 K. Incidential to this study is the determination of the frequency (wavelength) of a Xenon line in this region of the spectrum found at 13 663.274 K (731.6874 nm), with the same uncertainty level as the OH lines.